MikaStars39/nano-eval huggingface dataset:
The length of the line is 300 km, $αl=1 8^{\circ}, \, X_{\mathrm{S}} / Z_{\mathrm{C}}=0. 3, P^{*} \,=0. 7, Q^{*} \,=0. 2 2$. After load shedding, $S_{\mathrm{f}}=1. 0 5$. What is the multiplier $K_{2}$ for the voltage rise at the end of the no-load long line?

Options:
A. $$1.9$$
B. $$1.12$$
C. $$1.6$$
D. $$1.8$$
E. $$1.7$$
F. $$1.65$$
G. $$1.11$$
H. $$1.13$$
I. $$1.4$$
J. $$1.0$$
Answer: I
Due to the effects of radiation such as ultraviolet and cosmic rays, there are certain amounts of positive and negative ions in the atmosphere, each with a concentration of approximately $10^{3} \, \mathrm{cm^{-3}}$, and a recombination coefficient of $\rho \approx 10^{-6} \, \mathrm{cm}^{3} / \mathrm{s}$. What is the average lifespan of the ions?

Options:
A. $$1~\mathrm{ms}
$$
B. $$10~\mathrm{s}
$$
C. $$1~\mathrm{s}
$$
D. $$1~\mathrm{day}
$$
E. $$1~\mathrm{year}
$$
F. $$10~\mathrm{ms}
$$
G. $$1~\mathrm{hour}
$$
H. $$0.001~\mathrm{s}
$$
I. $$1~\mathrm{min}
$$
J. $$0.1~\mathrm{s}
$$
Answer: C
What is the safe distance from the wall for the 750kV power frequency test transformer and the 1.5MV lightning impulse voltage generator (the safety factor is approximately 1.8 for power frequency and approximately 1.3 for lightning impulse)?

Options:
A. $$4.8m,~3.2m$$
B. $$4.6m,~3.7m$$
C. $$4.7m,~3.4m$$
D. $$5.1m,~3.3m$$
E. $$4.5m,~3.51m$$
F. $$5.5m,~3.8m$$
G. $$4.9m,~3.5m$$
H. $$5.0m,~3.9m$$
I. $$4.3m,~3.4m$$
J. $$4.2m,~3.6m$$
Answer: E
It is necessary to measure the 50% flashover voltage of 7 XP-70 suspension insulators. The test waveform is a positive standard lightning impulse voltage. The flashover voltage is measured using a 1m diameter sphere gap. The measured sphere gap distance is 26.55 cm, and the atmospheric conditions during the test are: pressure 102.6 kPa, dry bulb temperature 14°C, and wet bulb temperature 9°C. What will be the flashover voltage of the insulator string under standard conditions?

Options:
A. $$
5 9 8. 2 1 k V
$$
B. $$
6 3 4. 4 3 k V
$$
C. $$
6 0 5. 4 4 k V
$$
D. $$
7 0 0. 5 7 k V
$$
E. $$
6 1 8. 9 8 k V
$$
F. $$
6 2 3. 1 0 k V
$$
G. $$
6 7 5. 0 5 k V
$$
H. $$
7 2 0. 3 6 k V
$$
I. $$
6 5 0. 8 9 k V
$$
J. $$
6 4 7. 7 2 k V
$$
Answer: B
A $500 \mathrm{kV}$ gas-insulated cable features a phase-separated, enclosed coaxial cylindrical electrode structure, with the outer diameter of the conductive core measuring $89 \mathrm{mm}$ and the inner diameter of the shell being 248mm. The gas pressure at 20°C is 0.4MPa. What is the breakdown voltage of this slightly non-uniform electric field gas gap? How much margin does it have compared to the 500kV system's impulse insulation level requirement of 1550kV?

Options:
A. $$
3225.8\mathrm{kV},~1 2 4. 6 \%
$$
B. $$
2875.3\mathrm{kV},~8 2. 4 \%
$$
C. $$
3332.4\mathrm{kV},~1 3 5. 0 \%
$$
D. $$
3062.9\mathrm{kV},~9 1. 2 \%
$$
E. $$
2990.1\mathrm{kV},~9 8. 1 \%
$$
F. $$
2938.5\mathrm{kV},~8 7. 7 \%
$$
G. $$
3280.0\mathrm{kV},~1 3 1. 6 \%
$$
H. $$
3040.7\mathrm{kV},~8 9. 8 \%
$$
I. $$
3150.6\mathrm{kV},~1 1 4. 7 \%
$$
J. $$
3105.7\mathrm{kV},~9 5. 3 \%
$$
Answer: I
Two containers filled with air, A and $\mathbf{B}$, are connected by a fine tube equipped with a piston. Container A is submerged in a water bath with a temperature of $t_{1}=100 \mathrm{°C}$, while container B is submerged in a coolant with a temperature of $t_{2}=-20 \mathrm{°C}$. Initially, the two containers are separated by the piston in the fine tube, and at this time, the air pressures in containers A and $\mathbf{B}$ are $p_{1}=0.0533 \text{ MPa}$ and $p_{2}=0.0200 \text{ MPa}$, respectively. Their volumes are $V_{1}=0.25 \ \mathrm{L}$ and $V_{2}=0.40 \ \mathrm{L}$. What will the pressure of the gas be after the piston is opened?

Options:
A. $$
1. 8 2 \times1 0^{4} \mathrm{Pa}
$$
B. $$
3. 3 0 \times1 0^{4} \mathrm{Pa}
$$
C. $$
1. 2 5 \times1 0^{4} \mathrm{Pa}
$$
D. $$
3. 6 0 \times1 0^{4} \mathrm{Pa}
$$
E. $$
2. 6 7 \times1 0^{4} \mathrm{Pa}
$$
F. $$
2. 9 8 \times1 0^{4} \mathrm{Pa}
$$
G. $$
1. 9 0 \times1 0^{4} \mathrm{Pa}
$$
H. $$
0. 8 9 \times1 0^{4} \mathrm{Pa}
$$
I. $$
4. 5 5 \times1 0^{4} \mathrm{Pa}
$$
J. $$
2. 5 5 \times1 0^{4} \mathrm{Pa}
$$
Answer: F
Using the effusion method, someone measured the vapor pressure of graphite. They found that at a temperature of 2603 $\mathbf{K}$, $0.648 \times 10^{-3} \mathrm{kg}$ of carbon passed through a small orifice of 3.25 $mm^{2}$ in 3.5 hours. Assuming the carbon vapor molecules are monatomic, what is the vapor pressure of graphite at 2603 $\mathbf{K}$ ?

Options:
A. $$
2. 5 \times1 0^{-5} \mathrm{~ P a}
$$
B. $$
4. 7 \times1 0^{-3} \mathrm{~ P a}
$$
C. $$
9. 2 \times1 0^{-2} \mathrm{~ P a}
$$
D. $$
6. 8 \times1 0^{-6} \mathrm{~ P a}
$$
E. $$
5. 3 \times1 0^{-2} \mathrm{~ P a}
$$
F. $$
1. 4 \times1 0^{-3} \mathrm{~ P a}
$$
G. $$
7. 6 \times1 0^{-8} \mathrm{~ P a}
$$
H. $$
1. 1 \times1 0^{-4} \mathrm{~ P a}
$$
I. $$
8. 0 \times1 0^{-2} \mathrm{~ P a}
$$
J. $$
3. 9 \times1 0^{-3} \mathrm{~ P a}
$$
Answer: E
A thermos bottle is filled with water of mass $m = 1.00$ kg. The inner surface area of the bottle's lining is $S = 700 \ \mathrm{cm}^{2}$, and the gap between the inner and outer containers is $d = 5.00 \mathrm{~mm}$. The pressure of the gas in the gap is $p = 1.00 \mathrm{~Pa}$. Assume that the heat loss inside the thermos bottle is solely through heat conduction by the gas in the gap. How long does it take approximately for the water temperature inside the container to drop from 90 $°C$ to 80 $°C$ ?
( considering the ambient temperature to be 20 $°C$ and assuming that the thermal conductivity of the gas in the layer is proportional to the gas pressure )

Options:
A. $$10h$$
B. $$12h$$
C. $$2h$$
D. $$3h$$
E. $$8h$$
F. $$6h$$
G. $$9h$$
H. $$4h$$
I. $$7h$$
J. $$5h$$
Answer: H
If the wavelength of a certain sound wave is equal to the mean free path of oxygen molecules under standard conditions, given that the diameter of an oxygen molecule is $3.00 \times 10^{-10} \mathrm{~m}$, what is the frequency of this sound wave?

Options:
A. $$
3. 6 1 \times1 0^{9} \mathrm{H z}
$$
B. $$
3. 0 4 \times1 0^{9} \mathrm{H z}
$$
C. $$
3. 7 5 \times1 0^{9} \mathrm{H z}
$$
D. $$
3. 2 5 \times1 0^{9} \mathrm{H z}
$$
E. $$
3. 8 8 \times1 0^{9} \mathrm{H z}
$$
F. $$
4. 2 1 \times1 0^{9} \mathrm{H z}
$$
G. $$
2. 8 3 \times1 0^{9} \mathrm{H z}
$$
H. $$
4. 0 0 \times1 0^{9} \mathrm{H z}
$$
I. $$
3. 3 3 \times1 0^{9} \mathrm{H z}
$$
J. $$
2. 9 9 \times1 0^{9} \mathrm{H z}
$$
Answer: I
In a container, there are several grams of ice at 0°C. If warm water at a temperature of $t_{1}=30 \mathrm{~°C}$ and mass of $m_{1}=30 \mathrm{~g}$ is poured into the container, the ice melts and the resulting temperature is half of the intended temperature. If an additional amount of warm water at $t_{1}=30 \mathrm{~°C}$ with a mass of $m_{2}=4 \mathrm{\ g}$ is added, the intended temperature is reached. Assuming the container does not absorb heat, give this intended temperature $t$ and the original mass $m$ of ice in the container.

Options:
A. $$5°C,20g$$
B. $$2°C,7g$$
C. $$10°C,9g$$
D. $$5°C,10g$$
E. $$8°C,13g$$
F. $$6°C,15g$$
G. $$9°C,11g$$
H. $$3°C,5g$$
I. $$7°C,12g$$
J. $$4°C,8g$$
Answer: D
A hot air balloon is crafted based on the principle that, as the temperature of a gas rises, it escapes from a container that is open to both the inside and outside, thereby generating lift. Consider a weather balloon with a volume of $V = 500 \ \mathrm{m}^{3}$, where the total mass of the balloon's envelope and equipment is $m = 85 \ \mathrm{kg}$. To enable it to ascend from the ground, to what temperature in Celsius should the air inside the balloon be heated?
If the balloon ascends to an altitude where the temperature is -23°C and the pressure is $p_{2} = 0.4 \times 10^{5} \ \mathrm{Pa}$, what should the temperature of the air inside the balloon be to maintain equilibrium at this position?
( It is known that the air temperature at ground level is 27°C, the atmospheric pressure is $p_{0} = 1 \times 10^{5} \ \mathrm{Pa}$, and the density of air under standard conditions is $\rho_{0} = 1.29 \ \mathrm{kg/m}^{3}$. )

Options:
A. $$52°C,74°C$$
B. $$65°C,90°C$$
C. $$79°C,85°C$$
D. $$61°C,92°C$$
E. $$18°C,40°C$$
F. $$47°C,80°C$$
G. $$29°C,57°C$$
H. $$34°C,68°C$$
I. $$12°C,56°C$$
J. $$23°C,45°C$$
Answer: C
The ultra-high frequency pulse machine emits pulses with an energy of $E=6 \mathrm{~J}$ each time and emits $f=500$ times per second, with an efficiency of $\eta=60\%$. To ensure that the temperature increase of the cooling water flowing through the water jacket of the pulse machine does not exceed $\Delta T=10 \ \mathrm{{}^{\circ} C}$, how many liters of water should flow through the water jacket per hour?

Options:
A. $$
1 5 0 \mathrm{~ L}
$$
B. $$
2 3 0 \mathrm{~ L}
$$
C. $$
1 3 5 \mathrm{~ L}
$$
D. $$
2 2 5 \mathrm{~ L}
$$
E. $$
1 9 0 \mathrm{~ L}
$$
F. $$
2 1 5 \mathrm{~ L}
$$
G. $$
1 8 0 \mathrm{~ L}
$$
H. $$
2 0 0 \mathrm{~ L}
$$
I. $$
1 7 2 \mathrm{~ L}
$$
J. $$
1 6 5 \mathrm{~ L}
$$
Answer: I
At what frequency does a 0.01 m diameter aluminum rod have equal phase velocities for transverse and longitudinal vibrations?

Options:
A. $$
f=2. 4 8 \times1 0^{6} \mathrm{~ H z}
$$
B. $$
f=6. 8 2 \times1 0^{4} \mathrm{~ H z}
$$
C. $$
f=9. 9 4 \times1 0^{5} \mathrm{~ H z}
$$
D. $$
f=2. 2 0 \times1 0^{5} \mathrm{~ H z}
$$
E. $$
f=8. 5 7 \times1 0^{4} \mathrm{~ H z}
$$
F. $$
f=5. 7 1 \times1 0^{4} \mathrm{~ H z}
$$
G. $$
f=1. 9 3 \times1 0^{5} \mathrm{~ H z}
$$
H. $$
f=3. 2 5 \times1 0^{5} \mathrm{~ H z}
$$
I. $$
f=4. 0 6 \times1 0^{6} \mathrm{~ H z}
$$
J. $$
f=7. 1 3 \times1 0^{6} \mathrm{~ H z}
$$
Answer: H
The maximum tensile stress that aluminum can withstand is $2.0 \times 10^{8} \, \mathrm{N / m}^{2}$, and for steel, it is $1.0 \times 10^{9} \, \mathrm{N / m^{2}}$. Assuming the radius of the aluminum membrane is $0.01 \, \mathrm{m}$, what is the maximum fundamental frequency it can achieve? For a steel membrane with the same radius, what is the highest fundamental frequency it can reach? (Note that for membranes, the maximum frequency is independent of thickness.) (Assume the perimeter is fixed.)

Options:
A. $$ f=7. 7 \mathrm{~ k H z} ; 11. 2 \mathrm{~ k H z} $$
B. $$
f=1 0. 4 \mathrm{~ k H z} ; 1 3. 8 \mathrm{~ k H z}
$$
C. $$ f=2. 1 \mathrm{~ k H z} ; 2. 3 \mathrm{~ k H z} $$
D. $$ f=8. 2 \mathrm{~ k H z} ; 9. 5 \mathrm{~ k H z} $$
E. $$ f=5. 6 \mathrm{~ k H z} ; 6. 7 \mathrm{~ k H z} $$
F. $$ f=3. 5 \mathrm{~ k H z} ; 7. 2 \mathrm{~ k H z} $$
G. $$ f=6. 3 \mathrm{~ k H z} ; 8. 0 \mathrm{~ k H z} $$
H. $$ f=4. 4 \mathrm{~ k H z} ; 5. 8 \mathrm{~ k H z} $$
I. $$ f=12. 1 \mathrm{~ k H z} ; 14. 6 \mathrm{~ k H z} $$
J. $$ f=15. 0 \mathrm{~ k H z} ; 20. 0 \mathrm{~ k H z} $$
Answer: B
When the air temperature rises from 0°C to 80°C, the sound pressure amplitude of a plane sound wave remains constant. Calculate the percentage change in sound intensity and the change in sound intensity level.

Options:
A. $$
9 \%, 0. 9 \mathrm{~ d B}
$$
B. $$
1 2 \%, 0. 3 \mathrm{~ d B}
$$
C. $$
1 4 \%, 0. 7 \mathrm{~ d B}
$$
D. $$
2 2 \%, 1. 8 \mathrm{~ d B}
$$
E. $$
1 0 \%, 1. 5 \mathrm{~ d B}
$$
F. $$
8 \%, 2. 1 \mathrm{~ d B}
$$
G. $$
2 0 \%, 0. 8 \mathrm{~ d B}
$$
H. $$
1 1 \%, 2. 5 \mathrm{~ d B}
$$
I. $$
1 6 \%, 0. 2 \mathrm{~ d B}
$$
J. $$
1 8 \%, 1. 0 \mathrm{~ d B}
$$
Answer: C
A plane sound wave with an effective sound pressure of 50 Pa and a frequency of 1000 Hz is incident perpendicularly from water onto the interface between water and air. Determine: What is the effective sound pressure of the plane wave transmitted into the air? What are the sound intensities of the incident wave in the water and the transmitted wave in the air? If this plane wave is incident from water onto the interface between water and ice, recalculate all the aforementioned quantities. What is the sound power reflection coefficient of the ice layer? (Assume the $\rho c$ value of ice is $920 \times 3200 = 2.94 \times 10^{6} \, \mathrm{Rayl.}$)

Options:
A. $$
0. 0 2 8 0 {\mathrm{~ P a}} ; 1. 7 1 {\mathrm{~ m W / m}}^{2} \,, 1. 9 {\mathrm{~}} \mu{\mathrm{~ W / m}}^{2} \, ; 6 6. 9 {\mathrm{~ P a}}, 1. 4 {\mathrm{~ m W / m}}^{2} \, ; 0. 1 1 0
$$
B. $$
0. 0 3 0 5 {\mathrm{~ P a}} ; 1. 6 5 {\mathrm{~ m W / m}}^{2} \,, 2. 2 {\mathrm{~}} \mu{\mathrm{~ W / m}}^{2} \, ; 6 5. 3 {\mathrm{~ P a}}, 1. 2 {\mathrm{~ m W / m}}^{2} \, ; 0. 1 1 2
$$
C. $$
0. 0 2 7 0 {\mathrm{~ P a}} ; 1. 6 0 {\mathrm{~ m W / m}}^{2} \,, 1. 8 {\mathrm{~}} \mu{\mathrm{~ W / m}}^{2} \, ; 6 8. 5 {\mathrm{~ P a}}, 1. 7 {\mathrm{~ m W / m}}^{2} \, ; 0. 1 0 7
$$
D. $$
0. 0 2 8 1 {\mathrm{~ P a}} ; 1. 6 9 {\mathrm{~ m W / m}}^{2} \,, 1. 9 {\mathrm{~}} \mu{\mathrm{~ W / m}}^{2} \, ; 6 6. 5 {\mathrm{~ P a}}, 1. 5 {\mathrm{~ m W / m}}^{2} \, ; 0. 1 0 9
$$
E. $$
0. 0 3 0 0 {\mathrm{~ P a}} ; 1. 7 0 {\mathrm{~ m W / m}}^{2} \,, 2. 0 {\mathrm{~}} \mu{\mathrm{~ W / m}}^{2} \, ; 6 5. 0 {\mathrm{~ P a}}, 1. 3 {\mathrm{~ m W / m}}^{2} \, ; 0. 1 0 8
$$
F. $$
0. 0 2 7 9 {\mathrm{~ P a}} ; 1. 6 2 {\mathrm{~ m W / m}}^{2} \,, 1. 5 {\mathrm{~}} \mu{\mathrm{~ W / m}}^{2} \, ; 6 7. 2 {\mathrm{~ P a}}, 1. 3 {\mathrm{~ m W / m}}^{2} \, ; 0. 1 1 3
$$
G. $$
0. 0 2 9 0 {\mathrm{~ P a}} ; 1. 7 3 {\mathrm{~ m W / m}}^{2} \,, 1. 7 {\mathrm{~}} \mu{\mathrm{~ W / m}}^{2} \, ; 6 5. 8 {\mathrm{~ P a}}, 1. 5 {\mathrm{~ m W / m}}^{2} \, ; 0. 1 0 6
$$
H. $$
0. 0 2 6 5 {\mathrm{~ P a}} ; 1. 6 3 {\mathrm{~ m W / m}}^{2} \,, 2. 0 {\mathrm{~}} \mu{\mathrm{~ W / m}}^{2} \, ; 6 9. 0 {\mathrm{~ P a}}, 1. 8 {\mathrm{~ m W / m}}^{2} \, ; 0. 1 0 5
$$
I. $$
0. 0 2 9 7 {\mathrm{~ P a}} ; 1. 5 9 {\mathrm{~ m W / m}}^{2} \,, 1. 8 {\mathrm{~}} \mu{\mathrm{~ W / m}}^{2} \, ; 6 8. 8 {\mathrm{~ P a}}, 1. 9 {\mathrm{~ m W / m}}^{2} \, ; 0. 1 0 4
$$
J. $$
0. 0 2 9 5 {\mathrm{~ P a}} ; 1. 6 8 {\mathrm{~ m W / m}}^{2} \,, 2. 1 {\mathrm{~}} \mu{\mathrm{~ W / m}}^{2} \, ; 6 7. 5 {\mathrm{~ P a}}, 1. 6 {\mathrm{~ m W / m}}^{2} \, ; 0. 1 1 1
$$
Answer: D
A large steel plate of 0.2 cm in water: try to compare the magnitude of the sound transmission coefficients of plane sound waves with frequencies of 15 kHz and 30 kHz vertically penetrating this plate. If there are voids in the steel plate, how will the sound transmission coefficient (i.e., the ratio of the refracted wave's sound intensity to that of the incident wave) change?

Options:
A. 0.82, 0.66; decrease.
B. 0.35, 0.78; no change.
C. 0.88, 0.34; enhancement.
D. 0.67, 0.19; augmentation.
E. 0.53, 0.26; stabilization.
F. 0.60, 0.40; constant flow.
G. 0.91, 0.61; increase.
H. 0.81, 0.51; reduction.
I. 0.72, 0.45; increase.
J. 0.44, 0.77; fluctuation.
Answer: H
A rectangular acoustic tube is used for testing sound-absorbing materials in the air, with a cross-sectional area of 0.4 m × 0.6 m. If it is required to produce a single $( 0, 0 )$ mode wave in the tube during testing, what should be the maximum test frequency in hertz?

Options:
A. $$
3 5 0 \mathrm{~ H z}
$$
B. $$
4 5 0 \mathrm{~ H z}
$$
C. $$
4 0 0 \mathrm{~ H z}
$$
D. $$
3 1 0 \mathrm{~ H z}
$$
E. $$
2 8 0 \mathrm{~ H z}
$$
F. $$
2 5 0 \mathrm{~ H z}
$$
G. $$
3 7 5 \mathrm{~ H z}
$$
H. $$
3 0 0 \mathrm{~ H z}
$$
I. $$
2 8 6 \mathrm{~ H z}
$$
J. $$
3 2 5 \mathrm{~ H z}
$$
Answer: I
A cylindrical air tube with a radius of 0.05 m and a length of 1 m has a planar piston sound source (radius 0.05 m, mass 0.015 kg, with a uniform vibrational velocity distribution on its surface) mounted at one end, while the other end is equipped with an infinitely large baffle. The question is: What is the mechanical impedance of the piston source system (including the loading effect of the air in the tube) when the vibration frequency of the piston source is 150 Hz? At this frequency, what is the amplitude of the force needed to achieve a piston surface displacement amplitude of 0.005 m? What is the acoustic power radiated from the open end, in watts?

Options:
A. (0.029+j12.9)N·s/m;67N;0.37W
B. (0.028+j13.9)N·s/m;63N;0.34W
C. (0.033+j12.2)N·s/m;61N;0.30W
D. (0.030+j13.4)N·s/m;64N;0.33W
E. (0.031+j13.0)N·s/m;60N;0.31W
F. (0.030+j11.8)N·s/m;59N;0.28W
G. (0.029+j13.2)N·s/m;62N;0.32W
H. (0.032+j14.3)N·s/m;66N;0.36W
I. (0.027+j14.1)N·s/m;65N;0.35W
J. (0.035+j12.5)N·s/m;58N;0.29W
Answer: G
A direct-radiating loudspeaker with a radius of $0.15 \mathrm{~m}$ has a mechanical resonance frequency of 25 Hz when mounted on a wall. When mounted on a small closed box with a volume of 0.1 m$^{3}$, its mechanical resonance frequency increases to 50 Hz. Assuming the loudspeaker only has an air-loaded radiation resistance on one side, find the stiffness constant of the loudspeaker cone suspension system and the mass of the loudspeaker cone.

Options:
A. 2.75 × 10 $^{3}$ N/m; 0.075 kg
B. 2.57 × 10 $^{3}$ N/m; 0.090 kg
C. 3.00 × 10 $^{3}$ N/m; 0.078 kg
D. 2.20 × 10 $^{3}$ N/m; 0.085 kg
E. 2.00 × 10 $^{3}$ N/m; 0.060 kg
F. 2.37 × 10 $^{3}$ N/m; 0.085 kg
G. 2.00 × 10 $^{3}$ N/m; 0.092 kg
H. 1.45 × 10 $^{3}$ N/m; 0.070 kg
I. 3.10 × 10 $^{3}$ N/m; 0.080 kg
J. 1.99 × 10 $^{3}$ N/m; 0.065 kg
Answer: F
A dynamic microphone diaphragm has an area of 5 cm$^{2}$. When this diaphragm is replaced by a steel block of the same shape, in a free sound field generated by a 500 Hz sound source, the sound pressure produced on the surface is $\mathrm{1 / \mu bar}$. When the diaphragm is placed back on the microphone, the sound impedance measured on its outer surface is (20+j0) dyne·s/cm$^{5}$. Calculate the sound pressure generated on the diaphragm surface.

Options:
A. 1.0Pa
B. 2.0Pa
C. 0.6Pa
D. 0.8Pa
E. 1.5Pa
F. 0.2Pa
G. 0.1Pa
H. 1.2Pa
I. 0.5Pa
J. 0.3Pa
Answer: G
Above the sandy seabed at 20 meters, there is a line array 10A in length (with a wavelength ⋋ of 6 cm), with a beam aimed at the seabed at a grazing angle of 12°. Given that the source level of the emitted sound is 100 dB and the pulse width is 10 ms, neglecting absorption, find the level of seabed reverberation received.

Options:
A. 9.7dB
B. 17.5dB
C. 11.1dB
D. 13.5dB
E. 14.6dB
F. 16.9dB
G. 15.3dB
H. 10.8dB
I. 18.2dB
J. 12.4dB
Answer: J
The concentration of phosphorylase in the cell-free extract of Escherichia coli is 0.08 units/$ml$, with a specific activity of 0.0033 units/mg protein. A 50 ml portion of this solution is fractionated using ammonium sulfate precipitation, and the precipitate at 30%-50% saturation is dissolved in $10 ml$ of solution and dialyzed, resulting in a post-dialysis volume of $12 ml$, containing $30 mg$ of protein per ml. A $20 \ \mu l$ sample of the partially purified enzyme solution is used to catalyze a reaction under standard experimental conditions, with a reaction rate of 5.9 nM/min. Calculation: enzyme recovery rate is().

Options:
A. $$75.2\%$$
B. $$89.9\%$$
C. $$85.0\%$$
D. $$77.8\%$$
E. $$92.3\%$$
F. $$79.5\%$$
G. $$80.4\%$$
H. $$83.1\%$$
I. $$91.7\%$$
J. $$88.5\%$$
Answer: J
The excited state nucleus can return to the ground state by emitting a $\gamma$ photon. Let the mass of the ground state, that is, the rest mass of the nucleus, be $m_{0},$ and the excitation energy (the energy of the nucleus in this excited state minus the energy in the ground state) be $\Delta E$. What is the frequency of the emitted $\gamma$ photon ?

Options:
A. $$
\frac{\Delta E} {hc} \left[ 1+\frac{\Delta E} {2 ( \Delta E+m_{0} c^{2} )} \right]
$$
B. $$
\frac{c\Delta E} {h} - \frac{m_{0} c^{2}} {(\Delta E + m_{0})}
$$
C. $$
\frac{\Delta E} {h} \left( 1+\frac{\Delta E} {2 m_{0} c^{2} - \Delta E} \right)
$$
D. $$
\frac{\Delta E} {h} \left[ 1-\frac{2\Delta E} {m_{0} c^{2}} \right]
$$
E. $$
\frac{\Delta E} {h} \left[ 1+\frac{\Delta E} {2 (m_{0} c - \Delta E)} \right]
$$
F. $$
\frac{\Delta E} {h} \left[ 1-\frac{\Delta E} {2 ( \Delta E+m_{0} c^{2} )} \right]
$$
G. $$
\frac{\Delta E} {hc} - \frac{m_{0} c^{2}} {2 (\Delta E + m_{0} c^{2})} $$
$$
H. $$
\frac{\Delta E} {h} \left[ 1-\frac{\Delta E} {2 ( \Delta E-m_{0} c^{2} )} \right]
$$
I. $$
\frac{\Delta E} {h} \left[ 1-\frac{\Delta E} {m_{0} c^{2} + \Delta E} \right]
$$
J. $$
\frac{\Delta E} {2h} \left[ 1-\frac{\Delta E} {(\Delta E + m_{0} c^{2})} \right]
$$
Answer: F
The minimum energy required for protons emerging from the accelerator to collide with hydrogen gas and produce antiprotons is ____.

Options:
A. $$
5. 6 \mathrm{G e V}
$$
B. $$
4. 9 \mathrm{G e V}
$$
C. $$
7. 5 \mathrm{G e V}
$$
D. $$
16. 8 \mathrm{G e V}
$$
E. $$
5. 8 \mathrm{G e V}
$$
F. $$
8. 5 \mathrm{G e V}
$$
G. $$
6. 0 \mathrm{G e V}
$$
H. $$
6. 6 \mathrm{G e V}
$$
I. $$
7. 2 \mathrm{G e V}
$$
J. $$
9. 0 \mathrm{G e V}
$$
Answer: H
The $\rho^{0}$ meson is a meson resonance state with a mass of $769 \mathrm{MeV}$ and a width of $154 \mathrm{MeV}$. Experimentally, it can be produced by using a $\pi^{-}$ meson to strike a hydrogen target, resulting in $\pi^{-}+\mathrm{p} \to\rho^{0}+\mathrm{n}.$
What is the average decay distance of a $\rho^{0}$ with an energy of 5 GeV?

Options:
A. $$
7. 5 2 ( \mathrm{f m} )
$$
B. $$
5. 2 4 ( \mathrm{f m} )
$$
C. $$
9. 1 5 ( \mathrm{f m} )
$$
D. $$
6. 1 7 ( \mathrm{f m} )
$$
E. $$
8. 6 5 ( \mathrm{f m} )
$$
F. $$
8. 9 0 ( \mathrm{f m} )
$$
G. $$
8. 2 3 ( \mathrm{f m} )
$$
H. $$
6. 9 8 ( \mathrm{f m} )
$$
I. $$
7. 8 6 ( \mathrm{f m} )
$$
J. $$
9. 4 0 ( \mathrm{f m} )
$$
Answer: G
The charmed meson $\mathrm{D}^{0}$ (rest mass $m=1.86 \mathrm{GeV}$) travels $3 \mathrm{mm}$ in a bubble chamber before the total energy of its decay products is $20 \mathrm{GeV}$. What is the average lifetime of $\mathrm{D}^{0}$ in its rest frame ?

Options:
A. $$
0. 3 \times1 0^{-1 4} ( \mathrm{s} )
$$
B. $$
4. 9 \times1 0^{-1 2} ( \mathrm{s} )
$$
C. $$
2. 5 \times1 0^{-1 2} ( \mathrm{s} )
$$
D. $$
6. 4 \times1 0^{-1 3} ( \mathrm{s} )
$$
E. $$
8. 2 \times1 0^{-1 3} ( \mathrm{s} )
$$
F. $$
3. 1 \times1 0^{-1 2} ( \mathrm{s} )
$$
G. $$
1. 0 \times1 0^{-1 1} ( \mathrm{s} )
$$
H. $$
9. 8 \times1 0^{-1 0} ( \mathrm{s} )
$$
I. $$
7. 6 \times1 0^{-1 1} ( \mathrm{s} )
$$
J. $$
5. 7 \times1 0^{-1 0} ( \mathrm{s} )
$$
Answer: G
Given the velocity potential function $\varphi=0.04 x^{3}+a x y^{2}+b y^{3}$ for an incompressible flow in a plane, where $x$ and $y$ are measured in meters and $\varphi$ is in $\mathrm{m^{2}/s}$, find the pressure difference between points $A (0, 0)$ and $B (3, 4)$. Assume the fluid density $\rho = 1000 \mathrm{kg/m^{3}}$.

Options:
A. $$
3 5 0 0. 0 ( \mathrm{N / m^{2}} )
$$
B. $$
4 5 0 2. 0 ( \mathrm{N / m^{2}} )
$$
C. $$
3 0 0 0. 0 ( \mathrm{N / m^{2}} )
$$
D. $$
4 5 7 0. 0 ( \mathrm{N / m^{2}} )
$$
E. $$
4 2 0 0. 0 ( \mathrm{N / m^{2}} )
$$
F. $$
4 5 0 0. 0 ( \mathrm{N / m^{2}} )
$$
G. $$
5 3 0 0. 0 ( \mathrm{N / m^{2}} )
$$
H. $$
5 0 0 0. 0 ( \mathrm{N / m^{2}} )
$$
I. $$
4 9 0 0. 0 ( \mathrm{N / m^{2}} )
$$
Answer: F
For a specific non-self-weight collapsible loess sample, the water content $w=15.6\%$, the relative density (specific gravity) of soil particles $D_{\mathrm{r}}=2.70$, the mass density $\rho=1.60 \mathrm{g/cm}^{3}$, the liquid limit $w_{\mathrm{L}}=30.0\%$, and the plastic limit $w_{\mathrm{P}}=17.9\%$. When designing the pile foundation, it is necessary to refer to the design parameters based on the liquidity index in a saturated state. Which of the following options does the liquidity index most closely match when the sample's degree of saturation reaches 85%?

Options:
A. 0.85
B. 0.67
C. 1.18
D. 0.94
E. 0.76
F. 0.92
G. 1.05
H. 0.99
I. 1.12
J. 1.21
Answer: H
Certain physical properties of the fine-grained soil layer in a building foundation are as follows: density $\rho/ 1.95 \mathrm{g/cm}^{3}$, relative density $d_{m}$ 2.70 specific gravity, water content $w/23\%$, liquid limit $w_{\mathrm{L}}/21\%$, and plastic limit $w_{p}/12\%$. Based on this, please name and describe the state of this soil layer and identify which of the following options is correct.

Options:
A. Sandy loam, wet, unstable
B. Chalky soil, dry, stable
C. Clay-loam blend, moist, dense
D. Gravelly soil, moist, rigid
E. Peaty soil, saturated, dense
F. Sandy soil, dry, loose
G. Silt-clay mix, dry, compacted
H. Clayey soil, moist, soft
I. Silty soil, wet, compacted
J. Loamy soil, saturated, flexible
Answer: I
A certain foundation pit is 30 meters long and 20 meters wide. From 0 to 15 meters in the site is a sand layer, with a permeability coefficient of 0.9 meters per day. The groundwater table is 2.0 meters deep, and it is required that the water level in the foundation pit be lowered to 7.0 meters below the surface. The foundation pit is far from any surface water bodies and aquiclude boundaries. The pumping well is 15 meters deep, and below 2.0 meters is fitted with a filter. According to the "Technical Code for Ground Treatment of Buildings" (JGJ 120-1999), the water inflow of this foundation pit most closely approximates is () tons.

Options:
A. 320
B. 215
C. 180
D. 290
E. 300
F. 245
G. 270
H. 235
I. 275
J. 260
Answer: F
On a uniform soil layer, there is an oil tank with a diameter of 10m, with an average base pressure of 100kPa. It is known that the additional stress coefficient at a point 10m below the tank's foundation on the central axis of the oil tank is 0.285. Based on settlement observations, the settlement of the tank's central baseplate is 200mm, and the deep-layer settlement at a depth of 10m is 40mm. Using an approximate method, which option is closest to the back-calculated compression modulus of the soil layer within the 10m range?

Options:
A. 4.0MPa
B. 6.5MPa
C. 3.0MPa
D. 3.5MPa
E. 6.0MPa
F. 7.0MPa
G. 5.5MPa
H. 5.0MPa
I. 4.5MPa
J. 2.5MPa
Answer: A
One side of a certain high-rise raft-type residential building is equipped with an underground garage. The two parts of the underground structure are interconnected, both utilizing raft foundations, with the foundation depth 10 meters below the outdoor ground level. The average base pressure $p_{\mathrm{k}}$ for the residential building is 260 kN/m², while for the underground garage, it is 60 kN/m². The groundwater level is situated at a depth of 3.0 meters below the outdoor ground. To address the foundation's anti-buoyancy issue, a backfill about 0.5 meters thick is added above the basement slab of the underground garage, consisting of steel slag with a density of 35 kN/m³. The soil layer in the area is considered to have a density of 20 kN/m³, and the groundwater density is taken as $10 \mathrm{kN/m}^{3}$. According to the "Code for Design of Building Foundation" (GB 50007--2002), the bearing capacity of the residential building foundation $f_{n}$ is () kPa.

Options:
A. 263.7kPa
B. 280.5kPa
C. 310.3kPa
D. 250.0kPa
E. 292.6kPa
F. 241.2kPa
G. 285.4kPa
H. 299.8kPa
I. 320.0kPa
J. 275.9kPa
Answer: E
The box foundation of a certain building is 9 meters wide, 20 meters long, and buried at a depth of $d = 5 \text{m}$. The groundwater level is 2.0 meters below the surface. The soil distribution is as follows: the first layer consists of fill soil with a thickness of 1.5 meters and a unit weight $\gamma = 18.0 \, \text{kN/m}^3$; the second layer consists of clay with a thickness of 10 meters, with a unit weight $\gamma = 18.5 \, \text{kN/m}^3$ above the water table and 19.5 kN/m³ below it, $I_{L} = 0.73$, $e = 0.83$. The characteristic value of the bearing capacity of the clay-bearing layer determined by load tests is $f_{\text{ak}} = 190 \, \text{kPa}$. The characteristic value of the bearing capacity of the clay-bearing layer corrected for depth and width $f_{a}$ is closest to () kPa.

Options:
A. 292kPa
B. 235kPa
C. 245kPa
D. 305kPa
E. 300kPa
F. 190kPa
G. 240kPa
H. 315kPa
I. 310kPa
J. 225kPa
Answer: A
A certain bored pile has a diameter of 800mm, with the pile shaft extending 10m above the ground and penetrating 20m into the soil. The pile tip is embedded into relatively intact hard rock. The horizontal deformation coefficient of the pile, $\alpha$, is 0.520 (1/m). The pile top is hinged, and within the 5m range below the pile top, the spacing of the stirrups is 200mm. The pile is under axial compression, and the design value of the axial pressure at the pile top is 6800kN. The pile construction process coefficient, $\psi_{c}$, is 0.8. According to the Chinese "Technical Code for Building Pile Foundations" (JGJ 94-2008), what should the design value of the axial compressive strength of the concrete of the pile body not be less than?

Options:
A. 22MPa
B. 25MPa
C. 18MPa
D. 16MPa
E. 28MPa
F. 23MPa
G. 26MPa
H. 17MPa
I. 19MPa
J. 21MPa
Answer: J
In a certain project, steel pipe piles with a diameter of 800mm and $l=21\mathrm{m}$ are used. The pile top penetrates $2\mathrm{m}$ into the soil, and the pile end penetrates $23\mathrm{m}$ into the soil. The site condition is cohesive soil from a depth of $2 \sim 12 \mathrm{m}$ below the surface, with the standard value of the ultimate side resistance $q_{\mathrm{s1k}}=50 \mathrm{kPa}$; from $12 \sim 20 \mathrm{m}$ is a silt layer, $q_{\mathrm{s2k}}=60 \mathrm{kPa}$; from $20 \sim 30 \mathrm{m}$ is medium sand, $q_{\mathrm{s3k}}=80 \mathrm{kPa}$. The ultimate end resistance $q_{\mathrm{pk}}=7000 \mathrm{kPa}$. According to the Chinese "Technical Code for Building Pile Foundations" (JGJ 94-2008), calculate the standard value of the ultimate vertical bearing capacity of a single pile with a cross-shaped partition installed at the pile end of an open-ended steel pipe pile, $Q_{\mathrm{uk}}$. The result is ( ) kN.

Options:
A. $$
5. 4 \times1 0^{3} \mathrm{k N}
$$
B. $$
4. 9 \times1 0^{3} \mathrm{k N}
$$
C. $$
5. 9 \times1 0^{3} \mathrm{k N}
$$
D. $$
4. 7 \times1 0^{3} \mathrm{k N}
$$
E. $$
6. 1 \times1 0^{3} \mathrm{k N}
$$
F. $$
7. 0 \times1 0^{3} \mathrm{k N}
$$
G. $$
6. 3 \times1 0^{3} \mathrm{k N}
$$
H. $$
5. 2 \times1 0^{3} \mathrm{k N}
$$
I. $$
5. 6 \times1 0^{3} \mathrm{k N}
$$
J. $$
6. 4 \times1 0^{3} \mathrm{k N}
$$
Answer: C
To determine the bearing capacity of cement-soil mixed pile composite foundation, a static load test on a multi-pile composite foundation was conducted. The pile diameter is 500mm, arranged in an equilateral triangular pattern, with a pile center distance of 1.20m. What should be the diameter of the circular bearing plate for the three-pile composite foundation load test?

Options:
A. 2.05m
B. 2.10m
C. 2.28m
D. 2.14m
E. 2.19m
F. 2.22m
G. 2.11m
H. 2.00m
I. 2.30m
J. 2.50m
Answer: E
For a certain site, cement-mixed columns are planned to be used for ground reinforcement. It is known that the foundation depth is 2.0m, the diameter of the mixing column is 600mm, the column length is 14.0m, and the column strength is $f_{\mathrm{cu}}=0.8\, \mathrm{MPa}$. The column strength reduction factor is taken as $\eta=0.3$, the inter-column soil bearing capacity reduction factor is $\beta=0.6$, and the column end soil bearing capacity reduction factor is $\alpha=0.4$. The center-to-center spacing of the mixing columns is 1.0m, arranged in an equilateral triangular pattern. Which of the following options is appropriate for the characteristic value of the bearing capacity of the composite foundation with mixed columns?

Options:
A. 120.0kPa
B. 85.2kPa
C. 90.6kPa
D. 150.3kPa
E. 98.6kPa
F. 110.5kPa
G. 102.4kPa
H. 134.8kPa
I. 77.9kPa
J. 95.7kPa
Answer: E
A certain city's factory building uses a CFG pile composite foundation, with a natural foundation bearing capacity characteristic value of 140 kPa. The piles are 17 meters long, with a concrete strength grade of C25, a pile diameter of $0.4 \mathrm{m}$, and a pile spacing of 1.75 m, arranged in an equilateral triangle pattern. The average side resistance characteristic value of the soil around the piles is $q_{\mathrm{s}}=28 \mathrm{kPa}$, and the pile tip resistance characteristic value is $q_{\mathrm{p}}=700 \mathrm{kPa}$. The reduction coefficient of bearing capacity for the soil between piles is $\beta=0.8$. The composite foundation bearing capacity characteristic value is closest to ( )${kPa}$.

Options:
A. 240.7kPa
B. 290.8kPa
C. 294.6kPa
D. 285.5kPa
E. 305.1kPa
F. 260.3kPa
G. 310.2kPa
H. 275.4kPa
I. 320.0kPa
J. 250.6kPa
Answer: C
A certain residence has a strip foundation under the load-bearing wall, with a width of 1.2m and a burial depth of 1.0m. The load acting on the foundation from the superstructure is 120kN/m, and the average unit weight of the foundation and the soil above it is 20.0kN/m³. The site's soil conditions are as follows: the first layer is silty clay with a thickness of 1.0m and a unit weight of 17.5kN/m³; the second layer is muddy clay with a thickness of 15.0m, a unit weight of 17.8kN/m³, a moisture content of 65%, and a bearing capacity characteristic value of 45kPa; the third layer is a dense sand and gravel layer. The groundwater is 1.0m below the surface. The thickness of the cushion is ()m.

Options:
A. 1.4m
B. 1.8m
C. 2.0m
D. 1.3m
E. 1.9m
F. 1.7m
G. 1.6m
H. 2.5m
I. 1.5m
J. 2.2m
Answer: F
A certain dam foundation with a thickness of 2.0 m has a surface layer of silty sand, underlaid by a medium sand layer. The difference in hydraulic head between the top and bottom surface of the sandy soil at the downstream toe of the dam is 1.8 m. The silt layer has a porosity of 40% and a relative density of 2.65. The safety factor is set at 2.0, and the bulk density of the drainage cover layer is 1.85 g/cm³. The cover layer is located below the water level. According to the Chinese "Code for Design of Rolled Earth-Rock Dams" (SL 274-2001), the thickness of the drainage cover layer (with a bulk density of 1.85 g/cm³) is ()m.

Options:
A. 1.5m
B. 2.1m
C. 2.7m
D. 1.1m
E. 1.3m
F. 2.4m
G. 1.9m
H. 3.0m
I. 0.9m
J. 1.7m
Answer: G
Excavating a foundation pit with a depth of 15m on a homogeneous sandy soil foundation involves using spaced retaining piles and single-row anchor support. The pile diameter is $100 \, \mathrm{mm}$, the pile spacing is 1.6m, and the anchor is 3m from the ground surface. Given that the specific weight of the sandy soil is $\gamma = 20 \, \mathrm{kN/m^{3}}$, and the angle of internal friction is $\varphi = 30°$, with no ground load. According to the Chinese "Technical Code for Building Foundation Pit Support" (JGJ 120-1999), which of the following options is closest to the standard value of the horizontal force of the anchor $T_{c1}$ ?

Options:
A. 680kN
B. 480kN
C. 640kN
D. 620kN
E. 520kN
F. 590kN
G. 450kN
H. 530kN
I. 560kN
J. 710kN
Answer: F
Given that the site's seismic intensity is 7 degrees, the design basic seismic acceleration is 0.15g, and the seismic design group is the first group. For buildings constructed on type II sites, with a natural structural vibration period of 0.40s and a damping ratio of 0.05, when performing cross-sectional seismic checks on the building structure, which of the following options is closest to the corresponding horizontal seismic influence coefficient value?

Options:
A. 0.178
B. 0.145
C. 0.123
D. 0.089
E. 0.214
F. 0.192
G. 0.134
H. 0.167
I. 0.153
J. 0.106
Answer: J
Male, 32 years old. A few days ago, he developed a cough due to a cold. Today, he suddenly has a high fever, chills, pain in the lower right chest, worsening with coughing, and rust-colored sputum. He experiences shortness of breath after activity. Physical examination: temperature $^{\circ}C$, pulse $123$ beats/min, blood pressure $120/78$ mmHg. Percussion over the lower right lung reveals dullness, and breath sounds are diminished on auscultation. White blood cell count is $12 \times 10^9$/L, with neutrophils predominant.
Based on the above medical history, what is the most likely diagnosis for this patient?

Options:
A. Diagnosed with acute lung abscess. It must be differentiated from aspergillosis, pulmonary eosinophilia, pneumonia caused by multidrug-resistant organisms, connective tissue disorders, bronchiectasis, cardiogenic pulmonary edema, etc.
B. Diagnosed with viral pneumonia. It must be differentiated from bronchitis, asthma attacks, pneumonia caused by atypical pathogens like legionella, fungal infections, lung abscess, pulmonary embolism, etc.
C. Diagnosed with mycoplasma pneumonia. It must be differentiated from bronchopneumonia, sarcoidosis, pneumonia caused by anaerobic bacteria like bacteroides, non-infectious causes, pulmonary fibrosis, lung edema, etc.
D. Diagnosed with staphylococcal pneumonia. It must be differentiated from cough variant asthma, occupational lung disease, pneumonia caused by parasites, non-respiratory conditions, pneumothorax, chronic obstructive lung disease, etc.
E. Diagnosed with lobar pneumonia. It must be differentiated from histoplasmosis, cystic fibrosis complications, pneumonia caused by rare bacteria, immunological lung diseases, atelectasis, thoracic malignancies, etc.
F. Diagnosed with lung cancer. It must be differentiated from chronic bronchitis, tuberculosis, pneumonia caused by bacterial pathogens like streptococcus, fungal pneumonia, pulmonary effusion, reactive airways disease, etc.
G. Diagnosed with pneumococcal pneumonia. It must be differentiated from pulmonary tuberculosis, pneumonia caused by other pathogens such as staphylococcal pneumonia, Klebsiella pneumonia, viral or mycoplasma pneumonia, lung cancer, acute lung abscess, etc.
H. Diagnosed with chronic bronchitis. It must be differentiated from emphysema, primary pulmonary hypertension, pneumonia caused by protozoa, mixed connective tissue disease, lung hematomas, lung contusion, etc.
I. Diagnosed with bacterial pneumonia. It must be differentiated from asthma, allergic bronchopulmonary aspergillosis, pneumonia caused by common pathogens such as viral agents, fungal infections, interstitial lung disease, pleuritis, etc.
J. Diagnosed with Klebsiella pneumonia. It must be differentiated from idiopathic pulmonary fibrosis, lung metastasis, pneumonia caused by gram-negative organisms, mediastinal masses, foreign body aspiration, lung collapse, etc.
Answer: G
In the barometer, the reading is inaccurate due to the surface effect of mercury. Given that the surface tension coefficient of mercury is $\alpha = 0.49 \mathrm{N/m}$, the inner diameter of the barometer glass tube is $d = 2.0 \mathrm{mm}$, and the contact angle is $\theta = 180^{\circ}$. On a certain day, the barometer reading is $p = 1.000 \times 10^{5} \mathrm{Pa}_{o}$. Considering the capillary effect, the actual atmospheric pressure $p_{0}$ is ______.

Options:
A. $$
0. 9 8 \times1 0^{5} \mathrm{P a}
$$
B. $$
1. 0 0 \times1 0^{5} \mathrm{P a}
$$
C. $$
1. 5 0 \times1 0^{5} \mathrm{P a}
$$
D. $$
1. 0 5 \times1 0^{5} \mathrm{P a}
$$
E. $$
1. 0 4 \times1 0^{5} \mathrm{P a}
$$
F. $$
1. 0 2 \times1 0^{5} \mathrm{P a}
$$
G. $$
1. 0 6 \times1 0^{5} \mathrm{P a}
$$
H. $$
1. 0 3 \times1 0^{5} \mathrm{P a}
$$
I. $$
1. 0 1 \times1 0^{5} \mathrm{P a}
$$
J. $$
0. 9 9 \times1 0^{4} \mathrm{P a}
$$
Answer: I
The magnetic field strength of a certain nuclear magnetic resonance spectrometer is $1.4092T$. Determine the operating frequency for the following nuclei: $^{1}{H}$, $\mathrm{^{13}C}$, $\mathrm{^{19}F}$, $\mathrm{^{31}P}$. (Assume the $g$ factors for $^{1}{H}, \mathrm{{}^{13}C}, \mathrm{{}^{19}F}, \mathrm{{}^{31}P}$ are $(5.5854, 1.4048, 5.2560, 2.2632)$ respectively.)

Options:
A. $$59.69MHz, 15.28MHz, 55.44MHz, 24.35MHz$$
B. $$60.09MHz, 15.48MHz, 57.44MHz, 23.50MHz$$
C. $$59. 99MHz, 15.08MHz,56.44MHz,24.30MHz$$
D. $$60.00MHz, 15.00MHz, 56.00MHz, 24.00MHz$$
E. $$59.79MHz, 14.98MHz, 56.24MHz, 24.25MHz$$
F. $$59.89MHz, 15.18MHz, 56.54MHz, 24.40MHz$$
G. $$59.49MHz, 14.75MHz, 55.90MHz, 23.95MHz$$
H. $$58.99MHz, 15.10MHz, 56.88MHz, 24.15MHz$$
I. $$59.99MHz, 18.08MHz, 53.44MHz, 22.30MHz$$
J. $$59.59MHz, 15.38MHz, 56.74MHz, 24.20MHz$$
Answer: C
Find the most probable speed, average speed, and root mean square speed of oxygen at $17^{\circ} \ \mathrm{C}$.

Options:
A. $$
\approx3 8 0 \ ( \mathbf{m} \cdot\mathbf{s}^{-1} )
$$
$$
\approx440 \ ( \mathbf{m} \cdot\mathbf{s}^{-1} )
$$
$$
\approx479 \ ( \mathbf{m} \cdot\mathbf{s}^{-1} )
$$
B. $$
\approx3 6 9 \ ( \mathbf{m} \cdot\mathbf{s}^{-1} )
$$
$$
\approx429 \ ( \mathbf{m} \cdot\mathbf{s}^{-1} )
$$
$$
\approx460 \ ( \mathbf{m} \cdot\mathbf{s}^{-1} )
$$
C. $$
\approx3 5 8 \ ( \mathbf{m} \cdot\mathbf{s}^{-1} )
$$
$$
\approx425 \ ( \mathbf{m} \cdot\mathbf{s}^{-1} )
$$
$$
\approx467 \ ( \mathbf{m} \cdot\mathbf{s}^{-1} )
$$
D. $$
\approx3 7 5 \ ( \mathbf{m} \cdot\mathbf{s}^{-1} )
$$
$$
\approx432 \ ( \mathbf{m} \cdot\mathbf{s}^{-1} )
$$
$$
\approx473 \ ( \mathbf{m} \cdot\mathbf{s}^{-1} )
$$
E. $$
\approx3 4 1 \ ( \mathbf{m} \cdot\mathbf{s}^{-1} )
$$
$$
\approx412 \ ( \mathbf{m} \cdot\mathbf{s}^{-1} )
$$
$$
\approx451 \ ( \mathbf{m} \cdot\mathbf{s}^{-1} )
$$
F. $$
\approx3 8 7 \ ( \mathbf{m} \cdot\mathbf{s}^{-1} )
$$
$$
\approx439 \ ( \mathbf{m} \cdot\mathbf{s}^{-1} )
$$
$$
\approx475 \ ( \mathbf{m} \cdot\mathbf{s}^{-1} )
$$
G. $$
\approx3 9 5 \ ( \mathbf{m} \cdot\mathbf{s}^{-1} )
$$
$$
\approx455 \ ( \mathbf{m} \cdot\mathbf{s}^{-1} )
$$
$$
\approx490 \ ( \mathbf{m} \cdot\mathbf{s}^{-1} )
$$
H. $$
\approx3 7 8 \ ( \mathbf{m} \cdot\mathbf{s}^{-1} )
$$
$$
\approx436 \ ( \mathbf{m} \cdot\mathbf{s}^{-1} )
$$
$$
\approx482 \ ( \mathbf{m} \cdot\mathbf{s}^{-1} )
$$
I. $$
\approx3 9 0 \ ( \mathbf{m} \cdot\mathbf{s}^{-1} )
$$
$$
\approx446 \ ( \mathbf{m} \cdot\mathbf{s}^{-1} )
$$
$$
\approx490 \ ( \mathbf{m} \cdot\mathbf{s}^{-1} )
$$
J. $$
\approx3 6 5 \ ( \mathbf{m} \cdot\mathbf{s}^{-1} )
$$
$$
\approx415 \ ( \mathbf{m} \cdot\mathbf{s}^{-1} )
$$
$$
\approx450 \ ( \mathbf{m} \cdot\mathbf{s}^{-1} )
$$
Answer: F
The minimum distance that the human eye can distinguish at a clear distance is $0.1 \mathrm{~mm}$. To observe the details of a $0.25 \ \mu\mathrm{m}$ cell, what is the numerical aperture of this microscope? Assume the wavelength of the light used is $600 \mathrm{~nm}.$

Options:
A. 1.02
B. 1.46
C. 0.92
D. 1.58
E. 1.22
F. 1.12
G. 1.31
H. 0.85
I. 1.66
J. 1.36
Answer: B
A helium-neon laser emits a laser beam with a wavelength of $0.6328 \mu\mathrm{m}$ and a power of $3 \mathrm{mW}$, with a beam divergence angle of $0.02 \mathrm{mrad}$, and a discharge capillary diameter of 1 mm. If it is projected onto a screen 10 meters away, what is the illumination on the screen?

Options:
A. $$
E_{\mathrm{v}}=8. 3 7 \times1 0^{5} \mathrm{l x}
$$
B. $$
E_{\mathrm{v}}=2. 6 3 \times1 0^{5} \mathrm{l x}
$$
C. $$
E_{\mathrm{v}}=9. 0 0 \times1 0^{5} \mathrm{l x}
$$
D. $$
E_{\mathrm{v}}=4. 5 9 \times1 0^{5} \mathrm{l x}
$$
E. $$
E_{\mathrm{v}}=3. 5 8 \times1 0^{5} \mathrm{l x}
$$
F. $$
E_{\mathrm{v}}=7. 7 5 \times1 0^{5} \mathrm{l x}
$$
G. $$
E_{\mathrm{v}}=1. 8 4 \times1 0^{5} \mathrm{l x}
$$
H. $$
E_{\mathrm{v}}=5. 7 9 \times1 0^{5} \mathrm{l x}
$$
I. $$
E_{\mathrm{v}}=4. 2 6 \times1 0^{5} \mathrm{l x}
$$
J. $$
E_{\mathrm{v}}=6. 1 2 \times1 0^{5} \mathrm{l x}
$$
Answer: I
Try to calculate how many lumens (lm) of luminous flux a standard 100W tungsten filament lamp emits within a 0.2 steradian (sr) range. What is the total luminous flux it emits?

Options:
A. 26.75lm,1690lm
B. 29.00lm,1750lm
C. 23.75lm,1550lm
D. 27.23lm,1710lm
E. 31.00lm,1850lm
F. 28.50lm,1730lm
G. 24.50lm,1570lm
H. 30.00lm,1800lm
I. 25.00lm,1600lm
J. 27.50lm,1725lm
Answer: D
Given the area of the TGS pyroelectric detector $A_{\mathrm{d}}=4 \, \mathrm{mm}^{2}$, thickness $d=0.1 \, \mathrm{mm}$, and volumetric specific heat $c=1.67 \, \mathrm{J} \cdot \mathrm{cm}^{-3} \cdot \mathrm{K}^{-1}$, if it is considered as a black body, find the thermal time constant $\tau_{\mathrm{T}}$ at $T=300 \, \mathrm{K}$.
If the incident optical radiation $P_{\omega}=10 \, \mathrm{mW}$, with a modulation frequency of $1 \, \mathrm{Hz}$, (given the pyroelectric coefficient $\gamma=3.5 \times 10^{-8} \, \mathrm{C} \cdot \mathrm{K}^{-1} \cdot \mathrm{cm}^{-2})$, the output current is ().

Options:
A. $$
1.90ms
$$
$$
9. 01 \times 10^{-8} \frac{\alpha\Phi_{\omega}} {G \Big( 1 \,+\, \omega^{2} \tau_{H}^{2} \Big)^{1 / 2}} \; \mathrm{e}^{\mathrm{jωt}}
$$
B. $$
2.20ms
$$
$$
7. 88 \times 10^{-8} \frac{\alpha\Phi_{\omega}} {G \Big( 1 \,+\, \omega^{2} \tau_{H}^{2} \Big)^{1 / 2}} \; \mathrm{e}^{\mathrm{jωt}}
$$
C. $$
1.50ms
$$
$$
8. 32 \times 10^{-8} \frac{\alpha\Phi_{\omega}} {G \Big( 1 \,+\, \omega^{2} \tau_{H}^{2} \Big)^{1 / 2}} \; \mathrm{e}^{\mathrm{jωt}}
$$
D. $$
1.60ms
$$
$$
8. 93 \times 10^{-8} \frac{\alpha\Phi_{\omega}} {G \Big( 1 \,+\, \omega^{2} \tau_{H}^{2} \Big)^{1 / 2}} \; \mathrm{e}^{\mathrm{jωt}}
$$
E. $$
2.00ms
$$
$$
9. 12 \times 10^{-8} \frac{\alpha\Phi_{\omega}} {G \Big( 1 \,+\, \omega^{2} \tau_{H}^{2} \Big)^{1 / 2}} \; \mathrm{e}^{\mathrm{jωt}}
$$
F. $$
2.05ms
$$
$$
7. 54 \times 10^{-8} \frac{\alpha\Phi_{\omega}} {G \Big( 1 \,+\, \omega^{2} \tau_{H}^{2} \Big)^{1 / 2}} \; \mathrm{e}^{\mathrm{jωt}}
$$
G. $$
1.80ms
$$
$$
8. 19 \times 10^{-8} \frac{\alpha\Phi_{\omega}} {G \Big( 1 \,+\, \omega^{2} \tau_{H}^{2} \Big)^{1 / 2}} \; \mathrm{e}^{\mathrm{jωt}}
$$
H. $$
1.67ms
$$
$$
8. 7 9 \times1 0^{-8} \frac{\alpha\Phi_{\omega}} {G \Big( 1 \,+\, \omega^{2} \tau_{H}^{2} \Big)^{1 / 2}} \; \mathrm{e}^{\mathrm{jωt}}
$$
I. $$
1.45ms
$$
$$
8. 45 \times 10^{-8} \frac{\alpha\Phi_{\omega}} {G \Big( 1 \,+\, \omega^{2} \tau_{H}^{2} \Big)^{1 / 2}} \; \mathrm{e}^{\mathrm{jωt}}
$$
J. $$
1.75ms
$$
$$
8. 67 \times 10^{-8} \frac{\alpha\Phi_{\omega}} {G \Big( 1 \,+\, \omega^{2} \tau_{H}^{2} \Big)^{1 / 2}} \; \mathrm{e}^{\mathrm{jωt}}
$$
Answer: H
The mirrors in a He-Ne laser with an output wavelength of $\lambda=632.8 \, nm$ are formed by alternating coatings of ZnS and $ThF_2$ on glass, with refractive indices of 1.5 and 2.5 respectively for these two materials. How many bilayers need to be coated at the minimum to achieve a mirror reflection coefficient greater than 99.5%?

Options:
A. 14
B. 6
C. 13
D. 5
E. 7
F. 8
G. 10
H. 9
I. 11
J. 12
Answer: E
The same two sections of optical fiber are coupled. When $\mathbf{N A}=0.21$ and $a=25 \mu\mathbf{m}$, to ensure that the coupling loss is less than 0.3 dB, what is the maximum allowable gap?

Options:
A. 28μm
B. 30μm
C. 10μm
D. 35μm
E. 12μm
F. 15μm
G. 22μm
H. 20μm
I. 18μm
J. 25μm
Answer: F
What is the Laurent series of $f(z) = \frac{1}{z(z-1)}$ at $z = 0$, $z = 1$, and $z = a \, (a>1)$?

Options:
A. $$
f ( z )=\sum_{n=0}^{n} \left( \,-\, 1 \, \right)^{n} \, \frac{\left( \, a \,-\, 1 \, \right)^{n}}{\left( \, z \,-\, 1 \, \right)^{n+1}} \,+\, \sum_{n=0}^{n} \frac{n^{n} }{\left( \, z \,-\, a \, \right)^{n+1}}.
$$
B. $$
f ( z )=\sum_{n=0}^{n} \left( \,-\, 1 \, \right)^{n} \, \frac{\left( \, a \,-\, n \, \right)^{n}} {\left( \, z \,-\, n \, \right)^{n+1}} \,-\, \sum_{n=0}^{n} \left( \, n \, \right)^{n} \, \frac{a^{n}} {\left( \, z \,-\, 0 \, \right)^{n+1}}.
$$
C. $$
f ( z )=\int_{0}^{1} \left( \,-\, 1 \, \right)^{n} \, \frac{a^{n}}{\left( \, z \,-\, a \, \right)^{n+1}} \, dz \,+\, \sum_{n=0}^{\infty} \frac{1}{n} \frac{\left( \, 1 \,-\, a \, \right)^{n}}{\left( \, z \,-\, a \, \right)^{n+1}}.
$$
D. $$
f ( z )=\sum_{n=0}^{n} \frac{a^{n}} {\left( \, a \,-\, z \, \right)^{n+1}} \,-\, \sum_{n=0}^{n} \left( \, n \, \right)^{n} \, \frac{1}{\left( \, z \,-\, 0 \, \right)^{n+1}}.
$$
E. $$
f ( z )=\sum_{n=0}^{n} \left( \,-\, 1 \, \right)^{n} \, \frac{\left( \, a \,-\, 0 \, \right)^{n}} {\left( \, z \,-\, n \, \right)^{n+1}} \,-\, \sum_{n=0}^{n} \left( \,-\, a \, \right)^{n} \, \frac{n^{n}} {\left( \, z \,-\, a \, \right)^{n+1}}.
$$
F. $$
f ( z )=\sum_{n=0}^{n} \left( \,-\, 2 \, \right)^{n} \, \frac{\left( \, a \,-\, 2 \, \right)^{n}}{\left( \, z \,-\, a \, \right)^{n+1}} \,-\, \sum_{n=0}^{n} \frac{z^n} {\left( \, a \,-\, z \, \right)^{n+1}}.
$$
G. $$
f ( z )=\sum_{n=0}^{n} \left( \, 1 \, \right)^{n} \, \frac{\left( \, z \,-\, 1 \, \right)^{n}} {\left( \, z \,-\, a \, \right)^{n+1}} \,+\, \sum_{n=0}^{n} e^{an} \frac{z^{n}}{\left( \, z \,-\, a \, \right)^{n+1}}.
$$
H. $$
f ( z )=\sum_{n=0}^{n} \frac{1}{n!} \left( \,-\, 1 \, \right)^{n} \, \frac{\left( \, a \,-\, 1 \, \right)^{n}}{\left( \, z \,-\, 1 \, \right)^{n+1}}.
$$
I. $$
f ( z )=\sum_{n=0}^{n} \left( n \right)^{n} \, \frac{\left( \, z \,-\, 1 \, \right)^{n}} {\left( \, a \,-\, z \, \right)^{n+1}} \,-\, \sum_{n=0}^{n} \left( \,-\, 1 \, \right)^{n} \, \frac{a^{n}} {\left( \, z \,-\, a \, \right)^{n+1}}.
$$
J. $$
f ( z )=\sum_{n=0}^{n} \left( \,-\, 1 \, \right)^{n} \, \frac{\left( \, a \,-\, 1 \, \right)^{n}} {\left( \, z \,-\, a \, \right)^{n+1}} \,-\, \sum_{n=0}^{n} \left( \,-\, 1 \, \right)^{n} \, \frac{a^{n}} {\left( \, z \,-\, a \, \right)^{n+1}}.
$$
Answer: J
What are the diffusion coefficients of beryllium and graphite when $E=0.025 \mathrm{~eV}$?

Options:
A. $$0.0416m,~0.0917m$$
B. $$0.0494m,~0.0871m$$
C. $$0.0428m,~0.0856m$$
D. $$0.0382m,~0.0894m$$
E. $$0.0523m,~0.0835m$$
F. $$0.0440m,~0.0920m$$
G. $$0.0398m,~0.0952m$$
H. $$0.0459m,~0.0902m$$
I. $$0.0475m,~0.0889m$$
J. $$0.0501m,~0.0973m$$
Answer: A
A mixture of ammonia containing 15% liquid and 85% vapor, at a temperature of $-10^{\circ} C$, determine its specific enthalpy.(The saturation pressure is: 0.28993 MPa.)

Options:
A. $$2 6 8. 1 0 1 9k J / k g$$
B. $$2 9 7. 5 6 4 7k J / k g$$
C. $$2 9 3. 2 8 9 5k J / k g$$
D. $$2 5 0. 6 3 9 4k J / k g$$
E. $$3 3 0. 1 2 3 1k J / k g$$
F. $$2 8 0. 4 7 1 3k J / k g$$
G. $$2 7 5. 2 9 5 2k J / k g$$
H. $$3 2 1. 4 5 8 3k J / k g$$
I. $$3 0 5. 7 8 6 0k J / k g$$
J. $$1 4 8. 3 9 2 2k J / k g$$
Answer: C