MikaStars39/nano-eval huggingface dataset:
______ is used in atomization of metals.

Options:
A. Air compressor
B. Vacuum pump
C. Chemical mixer
D. Steam turbine
E. Electric coil
F. Water jet
G. Plasma torch
H. Sonic nozzle
I. Magnetic rotor
J. Argon arc
Answer: F
Powder of various ferrous and non-ferrous materials that become brittle on heating can be formed using ___.

Options:
A. Grinding
B. Molding
C. Sintering
D. Melting
E. Welding
F. Casting
G. Smelting
H. Crushing
I. Shredding
J. Cutting
Answer: H
The production of metal powders by electrolytic deposition is suitable for which metals?

Options:
A. Predominantly synthetic polymers
B. Mostly organic metals
C. Mainly gaseous compounds
D. Exclusively non-metallic minerals
E. Solely refractory ceramics
F. Mainly conductive polymer materials
G. Purely radioactive substances
H. Both ferrous and non-ferrous metals
I. Primarily only ferrous elements
J. Entirely chemical solutions
Answer: H
The rotating electrode process is commonly used to produce powders of which metal?

Options:
A. Iron
B. Zinc
C. Copper
D. Nickel
E. Platinum
F. Lead
G. Aluminum
H. Gold
I. Silver
J. Titanium
Answer: J
Which of the following rivers lies in a rift valley?

Options:
A. Kaveri
B. Indus
C. Narmada
D. Brahmaputra
E. Godavari
F. Krishna
G. Ganges
H. Mahanadi
I. Tapti
J. Yamuna
Answer: I
A set designer has selected a blue couch for a scene that will include several characters, Which color should the costume designer use when designing a costume for a character who will be siting in the couch and walking near it if the intent is to draw as much attention to the character as possible?

Options:
A. gray
B. beige
C. pink
D. brown
E. yellow
F. black
G. purple
H. blue
I. orange
J. green
Answer: I
Preventive interventions are designed to prevent potential or existing problems ().

Options:
A. Evolving into legal troubles
B. Resulting in social isolation
C. Causing sleep disruption
D. Becoming a chronic illness
E. Leading to financial ruin
F. Turning into academic failure
G. Escalating to relationship conflicts
H. Leading to mental health crises
I. Becoming a disability
J. Growing into addiction
Answer: I
The major aim of special education is().

Options:
A. To segregate children with special needs from the general school environment.
B. To eliminate all challenges faced by children with special needs.
C. To provide children with special needs all the same experiences as others.
D. To completely cure disabilities in children with special needs.
E. To integrate children with special needs into regular sports programs.
F. To ensure children with special needs achieve the highest academic scores.
G. To prioritize developing musical talents in children with special needs.
H. To solely focus on the vocational skills of children with special needs.
I. To treat children with special needs as medical cases rather than students.
J. To develop a realistic self-concept in children with special needs.
Answer: J
If the hearing impairment remains undetected, it can result in the student facing().

Options:
A. Minor behavioral improvements
B. Strengthened memory retention
C. Enhanced auditory sensitivity
D. Increased verbal fluency
E. Heightened academic skills
F. Notable emotional growth
G. Substantial educational disadvantage
H. Gradual physical enhancement
I. Improved social interactions
J. Reduced cognitive obstacles
Answer: G
The property which enables metals to be drawn into wire is known as().

Options:
A. Conductivity
B. Flexibility
C. Rigidity
D. Ductility
E. Brittleness
F. Plasticity
G. Elasticity
H. Permeability
I. Hardness
J. Malleability
Answer: D
Which of the following metal has face centred cubic structure?

Options:
A. Chromium
B. Titanium
C. Iron
D. Gold
E. Cobalt
F. Magnesium
G. Vanadium
H. Zinc
I. Niobium
J. Manganese
Answer: D
Nitrogen balance describes the relationship between protein intake and protein excretion, expressed in the formula ( ).

Options:
A. Nitrogen balance = nitrogen intake - (urinary metabolic nitrogen + fecal metabolic nitrogen + skin nitrogen loss)
B. Nitrogen balance = protein intake - (urinary nitrogen + fecal nitrogen + skin and other nitrogen deposits)
C. Nitrogen balance = dietary nitrogen intake - (urinary nitrogen waste + fecal nitrogen + skin nitrogen losses)
D. Nitrogen balance = nitrogen input - (urinary nitrogen + fecal nitrogen loss + skin nitrogen excretion)
E. Nitrogen balance = nitrogen intake - (urinary nitrogen excretion + fecal nitrogen + skin and other nitrogen losses)
F. Nitrogen balance = Nitrogen intake - (Urinary metabolic nitrogen + Fecal nitrogen + Skin nitrogen loss)
G. Nitrogen balance = nitrogen intake - (urinary nitrogen + fecal nitrogen + skin and other nitrogen losses)
H. Nitrogen balance = nitrogen consumption - (urinary nitrogen + fecal metabolic nitrogen + skin nitrogen losses)
I. Nitrogen balance = Nitrogen intake - Urinary metabolic nitrogen + Fecal metabolic nitrogen + Nitrogen loss from skin, etc.
J. Nitrogen balance = total nitrogen intake - (urinary nitrogen excretion + fecal nitrogen + skin nitrogen losses)
Answer: G
There are up to 30 sulfur compounds in garlic, with the one having the strongest biological activity being ().

Options:
A. Diallyl sulfide
B. Diallyl disulfide
C. Prostaglandin $\mathrm{C}$
D. Methanethiol complex
E. Polysulfide compound
F. Diallyl trisulfide
G. Dimethyl sulfide compound
H. Allyl methyl sulfide
I. Thiosulfate component
J. Prostaglandin $\mathrm{A}$
Answer: B
Infants younger than 6 months who are artificially or mixed-fed should be given formula milk with a protein content of ( ).

Options:
A. $1 0 \% \sim1 2 \%$
B. $<10\%$
C. $2 5 \% \sim3 0 \%$
D. $1 5 \% \sim2 0 \%$
E. $1 2 \% \sim1 8 \%$
F. $1 8 \% \sim2 0 \%$
G. $2 0 \% \sim2 5 \%$
H. $< 11\%$
I. $> 25\%$
Answer: E
Among the following indicators, the one primarily used to assess the nutritional status of infants and young children is ( ).

Options:
A. Height-for-Age Z-score
B. Maximum Heart Rate
C. Rohrer index
D. Bone Mineral Density
E. Kaup Index
F. Skinfold Thickness
G. Blood Pressure Index
H. Ideal Weight
I. Vervaeck Index
J. Body Mass Index
Answer: E
When nitrite poisoning occurs, apply $( \quad)$ for detoxification.

Options:
A. Meilan
B. Olive oil extract
C. $EDTA-Na_2Ca$
D. Sodium peroxide
E. Aspirin
F. Atropine
G. Thiol Antidote
H. Antibiotics
I. Vitamin B12
J. Iron supplements
Answer: A
Aesthetics deals with objects that are().

Options:
A. devoid of any sensory perception
B. rooted in logical reasoning only
C. subjective to emotional interaction
D. interpreted through universal laws
E. created solely for societal gain
F. equivalent to mathematical formulas
G. defined by their practical utility
H. not essential to our existence
I. unconcerned with scientific accuracy
J. formed by our historical narratives
Answer: H
The four main divisions of philosophy are metaphysics,epistemology,axiology,and().

Options:
A. aesthetics.
B. astrology.
C. psychology.
D. dialectics.
E. linguistics.
F. logic.
G. empiricism.
H. theology.
I. rhetoric.
J. mysticism.
Answer: F
Move the charged metal plate A closer to a neutral metal plate B, which has the same length and width as A, aligning the two plates to face each other. Assume the charge on plate A is $q_{A}$, the area of each plate is $S$, and the distance between them is $d \, (\ll \sqrt{S})$. Neglecting edge effects, what is the potential difference between the two plates? What would the result be if plate B is grounded?

Options:
A. $$
\frac{q_{A} d} {2 \varepsilon_{0} S};\ \frac{q_{A} d} {\epsilon_{\circ} S}
$$
B. $$
\frac{d S} {q_{A} \varepsilon_{0}};\ \frac{d S} {q_{A} \epsilon_{\circ}}
$$
C. $$
\frac{q_{A} S} {2 \varepsilon_{0} d};\ \frac{q_{A} S} {\epsilon_{\circ} d}
$$
D. $$
\frac{q_{A} \varepsilon_{0}} {2 S d};\ \frac{q_{A} \varepsilon_{0}} {S d}
$$
E. $$
\frac{\varepsilon_{0} q_{A}} {2 d S};\ \frac{\varepsilon_{0} q_{A}} {d S}
$$
F. $$
\frac{S d} {2 q_{A} \varepsilon_{0}};\ \frac{S d} {q_{A} \epsilon_{\circ}}
$$
G. $$
\frac{d q_{A}} {2 \epsilon_{\circ} S};\ \frac{d q_{A}} {\epsilon_{\circ} S}
$$
H. $$
\frac{\epsilon_{\circ} d} {2 q_{A} S};\ \frac{\epsilon_{\circ} d} {q_{A} S}
$$
I. $$
\frac{2 q_{A} d} {\varepsilon_{0} S};\ \frac{2 q_{A} d} {\epsilon_{\circ} S}
$$
Answer: A
Two coaxial conducting cylinders have an inner cylinder with an outer radius of $R_{1}$, and an outer cylinder with an inner radius of $R_{2}$ $( R_{2} < 2 R_{1})$. Between them, there are two layers of uniform dielectric material, with a boundary interface at radius $a$. The absolute permittivity of the inner layer is $\varepsilon_{1}$, and the absolute permittivity of the outer layer is $\varepsilon_{2} = \frac{\varepsilon_{1}}{2}$. The dielectric strength (i.e., breakdown field strength) for both materials is $E_{\mathrm{M}}$. When the voltage increases, what is the maximum permissible potential difference between the two cylinders?

Options:
A. $$
U_{\mathsf{M}}=E_{\mathsf{M}} a \operatorname{l n} {\frac{R_{1}^{2}} {R_{2} a}}
$$
B. $$
U_{\mathsf{M}}={\frac{3} {4}} E_{\mathsf{M}} a \operatorname{l n} {\frac{R_{1}^{2}} {a R_{2}}}
$$
C. $$
U_{\mathsf{M}}=E_{\mathsf{M}} R_{2} \operatorname{l n} {\frac{a R_{1}} {R_{2}^{2}}}
$$
D. $$
U_{\mathsf{M}}=E_{\mathsf{M}} a \operatorname{l n} {\frac{R_{2}^{2}} {R_{1} a}}
$$
E. $$
U_{\mathsf{M}}={\frac{1} {4}} E_{\mathsf{M}} R_{1} \operatorname{l n} {\frac{a^{2}} {R_{1} R_{2}}}
$$
F. $$
U_{\mathsf{M}}={\frac{1} {3}} E_{\mathsf{M}} R_{2} \operatorname{l n} {\frac{R_{2} R_{1}} {a^{2}}}
$$
G. $$
U_{\mathsf{M}}={\frac{1} {2}} E_{\mathsf{M}} R_{2} \operatorname{l n} {\frac{a R_{1}} {R_{2}^{2}}}
$$
H. $$
U_{\mathsf{M}}={\frac{1} {2}} E_{\mathsf{M}} a \operatorname{l n} {\frac{a R_{1}} {R_{2}^{2}}}
$$
I. $$
U_{\mathsf{M}}={\frac{1} {2}} E_{\mathsf{M}} a \operatorname{l n} {\frac{R_{2}^{2}} {a R_{1}}}
$$
J. $$
U_{\mathsf{M}}={\frac{1} {2}} E_{\mathsf{M}} R_{1} \operatorname{l n} {\frac{R_{2} a} {R_{1}^{2}}}
$$
Answer: I
A particle with a mass of $0.5 \ \mathrm{g}$ and a charge of $2.5 \times 10^{-8} \mathrm{~C}$ enters a uniform magnetic field $B$ on the Earth's surface with an initial horizontal speed of $6 \times 10^{4}$ m/s. What is the minimum value of $B$ required to keep it moving in the horizontal direction?

Options:
A. $$
B_{\mathrm{m i n}}={\frac{2 m g} {q v_{0}}}=6. 5 4 \, \mathrm{~ T}
$$
B. $$
B_{\mathrm{m i n}}={\frac{m g} {q v_{0}}}=3. 2 7 \, \mathrm{~ T}
$$
C. $$
B_{\mathrm{m i n}}={\frac{m g}{q\cdot 2 v_{0}}}=1. 6 3 \, \mathrm{~ T}
$$
D. $$
B_{\mathrm{m i n}}={\frac{m}{g q v_{0}}}=0. 3 2 \, \mathrm{~ T}
$$
E. $$
B_{\mathrm{m i n}}={\frac{0.5 g} {2 q v_{0}}}=1. 6 3 \, \mathrm{~ T}
$$
F. $$
B_{\mathrm{m i n}}={\frac{m g} {2 q}}=1. 6 3 \, \mathrm{~ T}
$$
G. $$
B_{\mathrm{m i n}}={\frac{2 m g} {q 2 v_{0}}}=3. 2 7 \, \mathrm{~ T}
$$
H. $$
B_{\mathrm{m i n}}={\frac{2 m g} {2 q v_{0}}}=0. 8 1 5 \, \mathrm{~ T}
$$
I. $$
B_{\mathrm{m i n}}={\frac{m g} {2 q v_{0}}}=1. 6 3 \, \mathrm{~ T}
$$
J. $$
B_{\mathrm{m i n}}={\frac{m v_{0}} {q g}}=6. 3 7 \, \mathrm{~ T}
$$
Answer: B
An infinite cylindrical conductor carries a uniform axial current with an intensity of $I$, and the conductor's relative permeability is $\mu_{\mathrm{r}}=1$. What is the magnetic energy stored per unit length within the conductor?

Options:
A. $\frac{\mu_{0} \, I} {1 6 \pi}$
B. $\frac{I^{2} \, \mu_{\mathrm{r}}} {1 6 \pi}$
C. $\frac{\mu_{0} \, I^{2}} {1 6 \pi}$
D. $\frac{\mu_{0} \, I^{2}} {4 \pi}$
E. $\frac{2 \mu_{0} \, I^{2}} {1 6 \pi}$
F. $\frac{\mu_{0} \, I^{2}} {8 \pi}$
G. $\frac{\mu_{0} \, I^{2}} {3 2 \pi}$
H. $\frac{\mu_{0} \, I^{2}} {1 2 \pi}$
I. $\frac{I^{2}} {1 6 \mu_{0} \, \pi}$
J. $\frac{\mu_{\mathrm{r}} \, I^{2}} {1 6 \pi}$
Answer: C
The parallel plate capacitor has a plate area of $S$ and a spacing of $d$. It is filled with a dielectric, whose permittivity varies, being $\varepsilon_{1}$ at one plate and $\varepsilon_{2}$ at the other plate. The permittivity at other locations is linearly related to the distance from the location where it is $\varepsilon_{1}$, neglecting edge effects. What is the capacitance $C$ of this capacitor?

Options:
A. $$
\frac{( \varepsilon_{2}-\varepsilon_{1} ) \varepsilon_{0} S} {d \operatorname{l n} \frac{\varepsilon_{2}} {\varepsilon_{1}}}
$$
B. $$
\frac{(\varepsilon_{1} + \varepsilon_{2}) \varepsilon_{0} S} {d ( \varepsilon_{2}-\varepsilon_{1} )}
$$
C. $$
\frac{( \varepsilon_{2}-\varepsilon_{1} ) \varepsilon_{0} S} {d (\varepsilon_{2} + \varepsilon_{1})}
$$
D. $$
\frac{2 (\varepsilon_{2} + \varepsilon_{1}) \varepsilon_{0} S} {d (\varepsilon_{2} - \varepsilon_{1})}
$$
E. $$
\frac{\varepsilon_{0} S (\varepsilon_{2} + \varepsilon_{1})} {d \sqrt{\frac{\varepsilon_{2}}{\varepsilon_{1}}}}
$$
F. $$
\frac{\varepsilon_{0} S (\varepsilon_{2} - \varepsilon_{1})} {d \operatorname{s} i n \frac{\varepsilon_{2}} {\varepsilon_{1}}}
$$
G. $$
\frac{\varepsilon_{0} S (\varepsilon_{2} - \varepsilon_{1})} {d \operatorname{cos} \frac{\varepsilon_{2}} {\varepsilon_{1}}}
$$
H. $$
\frac{(\varepsilon_{2} \times \varepsilon_{1}) \varepsilon_{0} S} {d (\varepsilon_{2} - \varepsilon_{1})}
$$
I. $$
\frac{(\varepsilon_{2}-\varepsilon_{1}) \varepsilon_{0} S \varepsilon_{2}} {d (\varepsilon_{1} + \varepsilon_{2})}
$$
J. $$
\frac{\varepsilon_{0} S (\varepsilon_{2} - \varepsilon_{1})} {d \operatorname{e}^ {\frac{\varepsilon_{2}} {\varepsilon_{1}}}}
$$
Answer: A
A conductor cylinder with a radius of $a$ is enclosed by a coaxial conductor cylinder with a radius of $b$, both having a length of $l$, and filled with a uniform dielectric medium with a permittivity of $\varepsilon$. The cylinder carries a charge of $Q$, and the cylindrical shell carries a charge of $-Q$, neglecting edge effects. What is the total electric field energy $W_{\mathrm{e}}$ within the entire dielectric medium?

Options:
A. $$
\frac{Q^{2}} {4 \, \pi\, \varepsilon\ \varepsilon_{0} \ l} \operatorname{l n} \left(\frac{b} {a}\right)^{2}
$$
B. $$
\frac{Q^{2}} {2 \, \pi\, \varepsilon\ \varepsilon_{0} \ l} \operatorname{l n} \frac{b} {a}
$$
C. $$
\frac{Q^{2}} {4 \, \pi\, \varepsilon\ \varepsilon_{0} \ l} \left(\frac{b} {a}\right)
$$
D. $$
\frac{Q^{2}} {\pi\, \varepsilon\ \varepsilon_{0} \ l} \operatorname{l n} \frac{b} {a}
$$
E. $$
\frac{Q^{2}} {4 \, \pi\, \varepsilon\ \varepsilon_{0} \ l} \operatorname{l n} \frac{b} {a}
$$
F. $$
\frac{Q^{2}} {4 \, \pi\, \varepsilon\ \varepsilon_{0} \ l} \operatorname{l n} \frac{a} {b}
$$
G. $$
\frac{Q^{2}} {8 \, \pi\, \varepsilon\ \varepsilon_{0} \ l} \operatorname{l n} \frac{b} {a}
$$
H. $$
\frac{Q^2} {4 \, \pi\, \varepsilon\ \varepsilon_{0} \ l}
$$
I. $$
\frac{Q^{2}} {4 \, \pi\, \varepsilon\ \varepsilon_{0} \ b} \operatorname{l n} \frac{b} {a}
$$
J. $$
\frac{Q^{2}} {4 \, \pi\, \varepsilon\ \varepsilon_{0} \ l} \left(\frac{a} {b}\right)
$$
Answer: E
Why are dye marking devices classified as pyrotechnics?

Options:
A. Color compounds are combusted in order to evaporate water.
B. End purposes are similar to those of the true pyrotechnic.
C. Enclosures are sealed tightly preventing oxygen diffusion needs.
D. Evaporative cooling counteracts the thermal instability of substances.
E. Emission spectra resemble those found in the photonics market.
F. Exothermic reactions release gases that remain tethered to a surface.
G. Electrochemical reactions cause prolonged temperature oscillations.
H. Explosive sounds are generated similar to firearm discharges.
I. External pressures facilitate chemical breakdown in climatic events.
J. Energy shifts occur during state transitions in metal compounds.
Answer: B
What methods are currently used to launch the MK 25 marker?

Options:
A. Launching by hand or by sonobuoy launchers
B. Firing by catapult or surface-to-air systems
C. Launching by railgun or underwater propulsion
D. Releasing by tethered balloons or drones
E. Dispatching by magnetic rail or drone launchers
F. Delivering by rail transport or guided rockets
G. Jettisoning by emergency chutes or gliders
H. Ejecting by torpedo tubes or satellite systems
I. Deploying by submarine or aerial delivery
J. Dropping by helicopter or long-range artillery
Answer: A
How can the rt-1489/ALE become declassified?

Options:
A. By removing the battery and crushing, mutilation, or burning of the modules.
B. By sending the device back to the manufacturer for inspection.
C. By leasing the equipment to an authorized military partner.
D. By deactivating the wireless function and encrypting data.
E. By installing a tamper-proof seal and monitoring remotely.
F. By installing an updated firmware from a certified technician.
G. By enclosing the device in a Faraday cage during use.
H. By applying thermal paste to the circuits and sealing them.
I. By replacing internal components with third-party equivalents.
J. By covering the device in protective foil and storing it safely.
Answer: A
What is the average burn time, in minutes, of a MK 25 MOD 3 marine location marker?

Options:
A. 19.5 TO 25.5
B. 14.0 TO 19.0
C. 16.0 TO 22.0
D. 13.5 TO 18.5
E. 11.5 TO 17.0
F. 17.5 TO 23.5
G. 18.0 TO 24.0
H. 10.5 TO 14.5
I. 12.0 TO 16.0
J. 15.0 TO 20.0
Answer: D
To extinguish an aircraft parachute flare that is burning in the open, which of the following methods should be used?

Options:
A. Sand, spread gently from a distance
B. CO2 extinguishers, in short bursts from afar
C. Airtight cover to starve oxygen supply
D. Wind, by creating strong natural drafts
E. Water, in flooding quantities & at low pressure
F. Dry chemical agents, dispersed evenly
G. Foam, in a controlled concentrated stream
H. Oil, poured steadily to drown the flames
I. Heavy blanket, carefully placed over flame
J. High-pressure water, applied through a hose
Answer: E
On what item can you find the precise instructions for using a MK 124 MOD 1 signal?

Options:
A. Sticker placed at the bottom of the signal
B. Instructions printed on the usage guide booklet
C. Information sheet located in the product box
D. Instruction card found within the signal container
E. Description noted in the emergency kit manual
F. Label on the outer surface of the signal
G. Text shown on the signal's manufacturer website
H. Markings detailed in the user safety pamphlet
I. Manual included inside the packaging
J. Engraved text on the side of the signal
Answer: F
When carried externally on a bomb rack, the pull ring & reinforced adhesive foil strip are removed from a MK 58 marine location marker by what means?

Options:
A. A proximity sensor
B. A safety pin
C. A thermal activation switch
D. A hydraulic trigger
E. A push button mechanism
F. A remote control unit
G. A pressure plate
H. A detonation cord
I. A magnetic sensor
J. An arming wire
Answer: J
What are pyrotechnics, as used in the military?

Options:
A. Produce a bright light for illumination or smoke for signaling
B. Produce camouflage patterns for concealment or stealth
C. Preserve critical information for decryption or intelligence
D. Serve as a durable covering for equipment or personnel
E. Act as protective barriers against shrapnel or debris
F. Boost electronic signals for radios or other devices
G. Function as stabilizing anchors in harsh weather conditions
H. Generate heavy noise for disorientation or disruption
I. Cause psychological effects for negotiation or communication
J. Provide nutrition and sustenance in emergency situations
Answer: A
If the radius of the sphere is given as 43m and the spherical excess as 186.54m, what is the area of a spherical triangle?

Options:
A. 6190.85 sq. m
B. 6018.59 sq. m
C. 6001.85 sq. m
D. 6019.85 sq. m
E. 6089.15 sq. m
F. 6109.85 sq. m
G. 6091.85 sq. m
H. 6091.58 sq. m
I. 6019.58 sq. m
J. 6199.85 sq. m
Answer: D
What fraction of the rest mass energy is released (in the form of radiation) when a mass $\Delta M$ is dropped from infinity onto the surface of a neutron star with $M=1~$$M_{\\⊙}$ and $R=1 0$ km?

Options:
A. ≈ 0. 1 5
B. ≈ 0. 0 5
C. ≈ 0. 2 0
D. ≈ 0. 0 8
E. ≈ 0. 0 2
F. ≈ 0. 3 0
G. ≈ 0. 4 0
H. ≈ 0. 2 5
I. ≈ 0. 1 0
J. ≈ 0. 0 7
Answer: A
The density of stars in a particular globular star cluster is $1 0^{6} ~f\mathrm{p c}^{-3}$. Take the stars to have the same radius as the Sun, and to have an average speed of 10 km $\mathrm{s e c}^{-1}$. Find the mean free path for collisions among stars. Find the corresponding mean time between collisions. (Assume that the stars move in straight-line paths, i.e., are not deflected by gravitational interactions.)

Options:
A. $$\simeq6 \times1 0^{1 3} ~\mathrm{y e a r s}$$
B. $$\simeq1 \times1 0^{1 4} ~\mathrm{y e a r s}$$
C. $$\simeq2 \times1 0^{1 3} ~\mathrm{y e a r s}$$
D. $$\simeq2 \times1 0^{1 1} ~\mathrm{y e a r s}$$
E. $$\simeq5 \times1 0^{1 2} ~\mathrm{y e a r s}$$
F. $$\simeq9 \times1 0^{1 1} ~\mathrm{y e a r s}$$
G. $$\simeq8 \times1 0^{1 2} ~\mathrm{y e a r s}$$
H. $$\simeq4 \times1 0^{1 5} ~\mathrm{y e a r s}$$
I. $$\simeq7 \times1 0^{1 3} ~\mathrm{y e a r s}$$
J. $$\simeq3 \times1 0^{1 4} ~\mathrm{y e a r s}$$
Answer: A
A collimated light beam propagating in water is incident on the surface (air/water interface) at an angle $\theta_{\mathrm{w a t e r}}$ with respect to the surface normal. If the index of refraction of water is $n=1. 3$, find an expression for the angle of the light once it emerges from the water into the air, $\theta_{\mathrm{a i r}}$. What is the critical angle, i.e., $\theta_{\mathrm{w a t e r}}=\theta_{\mathrm{c r i t}}$, such that the light will not emerge from the water?

Options:
A. 48.12°
B. 49.77°
C. 52.43°
D. 50.28°
E. 54.11°
F. 47.89°
G. 51.94°
H. 50.05°
I. 52.89°
J. 53.27°
Answer: D
A binary system consists of two stars in a circular orbit about a common center of mass with an orbital period, $P_{\mathrm{o r b}}=1 0$ days. Star 1 is observed in the visible band, and Doppler measurements show that its orbital speed is $v_{1}=2 0$ km $\mathrm{s}^{-1}$. Star 2 is an $\mathrm{X}$ -ray pulsar and its orbital radius about the center of mass is $r_{2}=3 \times1 0^{1 2} \mathrm{~ c m}=3 \times1 0^{1 0}$ m.

Options:
A. $$1 0 ~M_{\odot}$$
B. $$1 5 ~M_{\odot}$$
C. $$1 7 ~M_{\odot}$$
D. $$1 6 ~M_{\odot}$$
E. $$1 4 ~M_{\odot}$$
F. $$1 9 ~M_{\odot}$$
G. $$1 1 ~M_{\odot}$$
H. $$1 8 ~M_{\odot}$$
I. $$1 3 ~M_{\odot}$$
J. $$1 2 ~M_{\odot}$$
Answer: E
What should be the CMRR of the preamplifier upto 5 kHz?

Options:
A. 30 dB
B. less than 90 dB
C. up to 75 dB
D. less than 10 dB
E. 10 dB
F. near 20 dB
G. between 45 and 60 dB
H. around 50 dB
I. exactly 60 dB
J. greater than 90 dB
Answer: J
If you were to perform an equivalent of the basic NMR experiment on a free electron (a.k.a. an ESR or electron spin resonance experiment), what field strength would you need to produce the same electron resonance frequency as you get from a proton NMR experiment?

Options:
A. 10.1 mT field
B. 2.3 mT field
C. 4.5 mT field
D. 3.6 mT field
E. 6.5 mT field
F. 5.2 mT field
G. 7.0 mT field
H. 0.9 mT field
I. 1.1 mT field
J. 8.3 mT field
Answer: B
Male, 60 years old, with a right inguinal hernia. After hernia repair surgery, how long does it take for the wound's tensile strength to reach its peak?

Options:
A. Four days
B. one year
C. Two weeks
D. Eight weeks
E. One month
F. Ten days
G. Three months
H. Nine months
I. Six months
J. Five months
Answer: G
Male, 45 years old, abdominal pain, and purulent bloody stool for 5 days, experiencing increasing fatigue, thus seeks consultation. Stool routine: WBC 15~30/hpf occasionally clustered pus cells, RBC 3~6/hpf. Fecal immunoassay: positive for Shigella antigen. Urinalysis (-). The most likely intestinal lesion for this patient is ().

Options:
A. Crohn's disease
B. Toxic megacolon
C. Allergic colitis
D. Peptic ulcer disease
E. Cellulosic inflammation
F. Intestinal tuberculosis
G. Chronic ulcerative colitis
H. Ischemic colitis
I. Erosive gastritis
J. Infectious ileitis
Answer: E
Autopsy revealed that the deceased's kidneys had reduced in size and weight, each weighing only 100g. They were hard in texture, with a thinned cortex and a granular surface. Upon examination of kidney sections, changes such as hyaline degeneration of arterioles and glomerular fibrosis were observed. What disease might this patient have suffered from during their lifetime?

Options:
A. Polycystic kidney disease
B. Lupus nephritis
C. Renal cysts
D. Diabetes
E. Urinary tract infection
F. Congenital dysplasia
G. Chronic pyelonephritis
H. Acute nephritis
I. Hypertension
J. Glomerulonephritis
Answer: I
There are four symbols, with the probabilities of the first three symbols appearing being 1/4, 1/8, and 1/8, respectively, and the appearance of each symbol is relatively independent. Calculate the average amount of information for this set of symbols.

Options:
A. $0. 8 bit/symbol$
B. $1. 2 bit/symbol$
C. $1. 7.5 bit/symbol$
D. $2. 0 bit/symbol$
E. $0. 5 bit/symbol$
F. $1. 9 bit/symbol$
G. $1. 0 bit/symbol$
H. $1. 3 bit/symbol$
I. $1. 1 bit/symbol$
J. $2. 4 bit/symbol$
Answer: C
Given a receiver input circuit with an equivalent resistance of 600Ω, an input circuit bandwidth of 6MHz, and an ambient temperature of $27^{\circ} \mathrm{C}$, calculate the equivalent value of thermal noise voltage generated by the circuit.

Options:
A. $$
V=3. 7 9 \times1 0^{-6} ( \mathrm{V} ) $$
B. $$
V=2. 3 4 \times1 0^{-6} ( \mathrm{V} ) $$
C. $$
V=4. 9 2 \times1 0^{-6} ( \mathrm{V} ) $$
D. $$
V=9. 1 4 \times1 0^{-6} ( \mathrm{V} ) $$
E. $$
V=6. 8 0 \times1 0^{-6} ( \mathrm{V} ) $$
F. $$
V=7. 7 2 \times1 0^{-6} ( \mathrm{V} )
$$
G. $$
V=8. 5 9 \times1 0^{-6} ( \mathrm{V} ) $$
H. $$
V=5. 3 7 \times1 0^{-6} ( \mathrm{V} ) $$
I. $$
V=6. 1 5 \times1 0^{-6} ( \mathrm{V} ) $$
J. $$
V=1. 2 6 \times1 0^{-6} ( \mathrm{V} ) $$
Answer: F
In a binary bipolar digital baseband transmission system with inter-symbol interference, the signal voltage at the sampling time is known to be 1V, and the noise variance is $20 \mathrm{mW}$. Find the bit error rate of the system is().(assuming 0 and 1 are sent with equal probability).

Options:
A. $$
{\frac{1} {8}} \operatorname{e r f c} \left( {\frac{2 \sigma_{\mathrm{s}}} {\sqrt{3}}} \right).
$$
B. $$
{\frac{1} {10}} \operatorname{e r f c} \left( {\frac{3} {2 \sigma_{\mathrm{s}}}} \right).
$$
C. $$
{\frac{1} {11}} \operatorname{e r f c} \left( {\frac{1} {\sigma_{\mathrm{s}} \sqrt{3}}} \right).
$$
D. $$
{\frac{1} {9}} \operatorname{e r f c} \left( {\frac{1} {\sigma_{\mathrm{s}}^{3}}} \right).
$$
E. $$
{\frac{1} {5}} \operatorname{e r f c} \left( {\frac{2} {\sqrt{\sigma_{\mathrm{s}}}}} \right).
$$
F. $$
{\frac{1} {6}} \operatorname{e r f c} \left( {\frac{1} {2 \sigma_{\mathrm{s}}}} \right).
$$
G. $$
{\frac{1} {3}} \operatorname{e r f c} \left( {\frac{1} {\sigma_{\mathrm{s}}^{2}}} \right).
$$
H. $$
{\frac{1} {7}} \operatorname{e r f c} \left( {\frac{\sigma_{\mathrm{s}}} {\sqrt{2}}} \right).
$$
I. $$
{\frac{1} {2}} \operatorname{e r f c} \left( {\frac{1} {\sqrt{2} \sigma_{\mathrm{s}}}} \right).
$$
J. $$
{\frac{1} {4}} \operatorname{e r f c} \left( {\frac{\sigma_{\mathrm{s}}} {\sqrt{3}}} \right).
$$
Answer: I
An analog signal is sampled, quantized, and encoded into a PCM signal with a quantization level of 128, plus an additional 1 bit as a synchronization code for the codeword. This PCM signal is transmitted in a channel with a roll-off factor $\alpha=1$ and a bandwidth of $B=24 \mathrm{kHz}$. Find: What is the highest frequency of the analog signal?

Options:
A. $$
f_{\mathrm{H}}=\frac{2 f_{\mathrm{s}}} {3}=1 3 3 3 \mathrm{H z}_{\mathrm{m}}
$$
B. $$
f_{\mathrm{H}}=\frac{4 f_{\mathrm{s}}} {7}=1 4 2 8 \mathrm{H z}_{\mathrm{k}}
$$
C. $$
f_{\mathrm{H}}=\frac{7 f_{\mathrm{s}}} {10}=1 7 5 0 \mathrm{H z}_{\mathrm{l}}
$$
D. $$
f_{\mathrm{H}}=\frac{8 f_{\mathrm{s}}} {11}=1 9 0 9 \mathrm{H z}_{\mathrm{w}}
$$
E. $$
f_{\mathrm{H}}=\frac{3 f_{\mathrm{s}}} {5}=1 6 0 0 \mathrm{H z}_{\mathrm{t}}
$$
F. $$
f_{\mathrm{H}}=\frac{5 f_{\mathrm{s}}} {8}=1 8 7 5 \mathrm{H z}_{\mathrm{n}}
$$
G. $$
f_{\mathrm{H}}=\frac{f_{\mathrm{s}}} {2}=1 5 0 0 \mathrm{H z}_{\mathrm{s}}
$$
H. $$
f_{\mathrm{H}}=\frac{6 f_{\mathrm{s}}} {9}=1 5 5 5 \mathrm{H z}_{\mathrm{j}}
$$
I. $$
f_{\mathrm{H}}=\frac{1 f_{\mathrm{s}}} {4}=1 2 0 0 \mathrm{H z}_{\mathrm{p}}
$$
J. $$
f_{\mathrm{H}}=\frac{f_{\mathrm{s}}} {6}=1 2 5 0 \mathrm{H z}_{\mathrm{q}}
$$
Answer: G
If the sample value is $-139$ quantization units, then the polarity code for the A-law 13-segment linear quantization encoding is ____, and the segment code is ____.

Options:
A. 1,010
B. 1,000
C. 1,011
D. 0,000
E. 0,100
F. 0,110
G. 0,111
H. 1,001
I. 1,100
J. 0,101
Answer: E
In mobile communications, the transmitter's carrier frequency is $900 \mathrm{~MHz}$. A car is moving at a speed of 80 km/h. Try calculating the car's onboard receiver carrier frequency when the car is moving in a straight line towards the transmitter.

Options:
A. $$
f_{1}=f-\Delta f=( \, 8 9 5-0. \, 2 4 \, ) \, \mathrm{M H z}=8 9 4. \, 7 6 \, \mathrm{M H z}
$$
B. $$
f_{1}=f+\Delta f=( \, 9 9 0+0. \, 2 4 \, ) \, \mathrm{M H z}=9 9 0. \, 2 4 \, \mathrm{M H z}
$$
C. $$
f_{1}=f-\Delta f=( \, 9 0 0-0. \, 2 9 \, ) \, \mathrm{M H z}=8 9 9. \, 7 1 \, \mathrm{M H z}
$$
D. $$
f_{1}=f-\Delta f=( \, 9 0 0-0. \, 3 0 \, ) \, \mathrm{M H z}=8 9 9. \, 7 0 \, \mathrm{M H z}
$$
E. $$
f_{1}=f-\Delta f=( \, 8 9 0-0. \, 1 8 \, ) \, \mathrm{M H z}=8 8 9. \, 8 2 \, \mathrm{M H z}
$$
F. $$
f_{1}=f+\Delta f=( \, 9 5 0+0. \, 2 4 \, ) \, \mathrm{M H z}=9 5 0. \, 2 4 \, \mathrm{M H z}
$$
G. $$
f_{1}=f+\Delta f=( \, 9 0 5+0. \, 2 2 \, ) \, \mathrm{M H z}=9 0 5. \, 2 2 \, \mathrm{M H z}
$$
H. $$
f_{1}=f-\Delta f=( \, 9 0 0-0. \, 2 4 \, ) \, \mathrm{M H z}=8 9 9. \, 7 6 \, \mathrm{M H z}
$$
I. $$
f_{1}=f-\Delta f=( \, 9 0 0-0. \, 1 5 \, ) \, \mathrm{M H z}=8 9 9. \, 8 5 \, \mathrm{M H z}
$$
J. $$
f_{1}=f+\Delta f=( \, 9 0 0+0. \, 2 4 \, ) \, \mathrm{M H z}=9 0 0. \, 2 4 \, \mathrm{M H z}
$$
Answer: H
The amplitude range is a voice signal sample of $-1 \sim +1$ V. After being encoded with A-law 13-segment compression, the result is 01110001. After channel transmission, due to bit errors, the received code is 01100001. What is the output voltage error caused purely by the bit error in the decoding result? (Hint: Do not consider the error caused by quantization itself .

Options:
A. $$
\frac{3 5} {6 4}-\frac{3 7} {1 2 8}=\frac{3 3} {1 2 8} \mathrm{V}
$$
B. $$
\frac{3 4} {6 4}-\frac{3 9} {1 2 8}=\frac{2 9} {1 2 8} \mathrm{V}
$$
C. $$
\frac{3 7} {6 4}-\frac{3 8} {1 2 8}=\frac{3 5} {1 2 8} \mathrm{V}
$$
D. $$
\frac{3 1} {6 4}-\frac{3 3} {1 2 8}=\frac{3 0} {1 2 8} \mathrm{V}
$$
E. $$
\frac{3 6} {6 4}-\frac{3 5} {1 2 8}=\frac{3 1} {1 2 8} \mathrm{V}
$$
F. $$
\frac{3 9} {6 4}-\frac{3 1} {1 2 8}=\frac{3 7} {1 2 8} \mathrm{V}
$$
G. $$
\frac{3 5} {6 4}-\frac{3 4} {1 2 8}=\frac{3 2} {1 2 8} \mathrm{V}
$$
H. $$
\frac{3 0} {6 4}-\frac{3 0} {1 2 8}=\frac{3 4} {1 2 8} \mathrm{V}
$$
I. $$
\frac{3 2} {6 4}-\frac{3 6} {1 2 8}=\frac{2 8} {1 2 8} \mathrm{V}
$$
J. $$
\frac{3 8} {6 4}-\frac{3 2} {1 2 8}=\frac{3 6} {1 2 8} \mathrm{V}
$$
Answer: A
Given that the output noise power of a certain receiver is $10^{-9} \mathbf{W}$, the system uses coherent demodulation, and the output signal-to-noise ratio is 23dB. The total transmission loss from the transmitter to the receiver is $100 \mathrm{dB}$. What is the power of the transmitter when using single and double sideband modulation, respectively?

Options:
A. $2 \times1 0^{3} \, \mathrm{W} ;$ $9 \times1 0^{3} \, \mathbf{W}_{\circ}$
B. $7 \times1 0^{3} \, \mathrm{W} ;$ $5 \times1 0^{3} \, \mathbf{W}_{\circ}$
C. $9 \times1 0^{3} \, \mathrm{W} ;$ $6 \times1 0^{3} \, \mathbf{W}_{\circ}$
D. $8 \times1 0^{3} \, \mathrm{W} ;$ $4 \times1 0^{3} \, \mathbf{W}_{\circ}$
E. $3 \times1 0^{3} \, \mathrm{W} ;$ $8 \times1 0^{3} \, \mathbf{W}_{\circ}$
F. $6 \times1 0^{3} \, \mathrm{W} ;$ $3 \times1 0^{3} \, \mathbf{W}_{\circ}$
G. $5 \times1 0^{3} \, \mathrm{W} ;$ $2 \times1 0^{3} \, \mathbf{W}_{\circ}$
H. $4 \times1 0^{3} \, \mathrm{W} ;$ $7 \times1 0^{3} \, \mathbf{W}_{\circ}$
I. $9 \times1 0^{2} \, \mathrm{W} ;$ $5 \times1 0^{2} \, \mathbf{W}_{\circ}$
J. $1 \times1 0^{3} \, \mathrm{W} ;$ $1 \times1 0^{3} \, \mathbf{W}_{\circ}$
Answer: D
A resistive load is powered by a single-phase AC voltage regulation circuit, with a supply voltage of \( $U_{1} = 220 \, \mathrm{V}$ \). When \( $\alpha = 90^{\circ}$ \), find the effective value of the output voltage, effective current value, output power, and input power factor.

Options:
A. $$143.2V,14.32A,2000W,0.670$$
B. $$127.5V,12.75A,2100W,0.620$$
C. $$134.7V,13.47A,2200W,0.690$$
D. $$155.6V,15.56A,2420W,0.707$$
E. $$112.9V,11.29A,1850W,0.630$$
F. $$93.4V,9.34A,1800W,0.600$$
G. $$98.7V,9.87A,1950W,0.610$$
H. $$105.0V,10.50A,1750W,0.650$$
I. $$89.1V,8.91A,1600W,0.580$$
J. $$149.9V,14.99A,2300W,0.680$$
Answer: D
The resistance value $R = 10 \, \Omega$ and the inductance $L = 20 \, \mathrm{mH}$ are connected in series as the load, powered by a single-phase AC voltage regulation circuit with $U_{\mathrm{in}} = 220 \, \mathrm{V}$. Find: the maximum output power $P_{0}$ and the corresponding input power factor $\lambda$.

Options:
A. $$
3 2 5 0 \mathrm{W},0.75
$$
B. $$
4 2 0 0 \mathrm{W},0.82
$$
C. $$
3 4 0 0 \mathrm{W},0.87
$$
D. $$
3 6 0 0 \mathrm{W},0.78
$$
E. $$
3 7 5 0 \mathrm{W},0.84
$$
F. $$
3 3 0 0 \mathrm{W},0.88
$$
G. $$
4 0 0 0 \mathrm{W},0.80
$$
H. $$
3 4 7 1 \mathrm{W},0.85
$$
I. $$
3 6 5 0 \mathrm{W},0.81
$$
J. $$
3 5 0 0 \mathrm{W},0.90
$$
Answer: H
A boost chopper circuit with a filter capacitor of $C=470 \mu F$. It is desired that the output voltage $U_{O}=24 V$ and the output power $P_{O} \geq 12 W$. Try to calculate the minimum inductance $L_{m}$ required to keep the converter operating in continuous conduction mode when the power supply voltage $U_{s}$ is between 10 to 15V, with $T_{s}=20 \mu s$.

Options:
A. $$
0. 2 5 \mathrm{m H}
$$
B. $$
0. 0 9 \mathrm{m H}
$$
C. $$
0. 0 5 \mathrm{m H}
$$
D. $$
0. 0 8 \mathrm{m H}
$$
E. $$
0. 0 3 \mathrm{m H}
$$
F. $$
0. 0 6 \mathrm{m H}
$$
G. $$
0. 0 1 \mathrm{m H}
$$
H. $$
0. 1 0 \mathrm{m H}
$$
I. $$
0. 1 2 \mathrm{m H}
$$
J. $$
0. 0 7 \mathrm{m H}
$$
Answer: J
Inductive load with a significant inductance and resistance $R=5 \Omega$. The circuit uses a single-phase half-controlled bridge circuit with a freewheeling diode, and the input voltage is $U_{2}=220 \mathrm{V}$. When the control angle $\alpha=60^{\circ}$, find the average value $I_{\mathrm{dD}}$ and the effective value $I_{\mathrm{D}}$ of the current flowing through the freewheeling diode.

Options:
A. $$
I_{d D}==1 0 A,
$$
$$
I_{D}=1 7. 3 A
$$
B. $$
I_{d D}==8 5 A,
$$
$$
I_{D}=1 8. 7 A
$$
C. $$
I_{d D}==9 0 A,
$$
$$
I_{D}=1 6. 4 A
$$
D. $$
I_{d D}==6 5 A,
$$
$$
I_{D}=1 4. 0 A
$$
E. $$
I_{d D}==1 2 A,
$$
$$
I_{D}=1 9. 5 A
$$
F. $$
I_{d D}==1 3 A,
$$
$$
I_{D}=2 1. 8 A
$$
G. $$
I_{d D}==2 0 A,
$$
$$
I_{D}=1 6. 9 A
$$
H. $$
I_{d D}==1 5 A,
$$
$$
I_{D}=2 0. 0 A
$$
I. $$
I_{d D}==1 1 A,
$$
$$
I_{D}=1 5. 8 A
$$
J. $$
I_{d D}==7 5 A,
$$
$$
I_{D}=1 7. 2 A
$$
Answer: A
In the known three-phase fully-controlled bridge rectifier circuit, $U_{2}=230 \mathrm{V}$, $E_{\mathrm{M}}=290 \mathrm{V}$, and the total armature circuit resistance is $R=0.8 \, \Omega$. If the circuit operates in inversion mode and the current is continuous, with the permissible $I_{\mathrm{dmin}}=30 \mathrm{A}$, find $\beta_{\operatorname* {min}}$ and choose the thyristor's current and voltage rating accordingly.

Options:
A. $$
\beta_{\mathrm{m i n}}=6 0^{\circ}
$$
$$
U_{\mathrm{e}}=( 1 1 2 6. 7 7 {\sim} 1 6 9 0. 1 5 ) \mathrm{V}
$$
B. $$
\beta_{\mathrm{m i n}}=1 5^{\circ}
$$
$$
U_{\mathrm{e}}=( 8 6 2. 1 1 {\sim} 1 3 7 4. 9 6 ) \mathrm{V}
$$
C. $$
\beta_{\mathrm{m i n}}=4 5^{\circ}
$$
$$
U_{\mathrm{e}}=( 1 0 5 4. 2 2 {\sim} 1 5 8 0. 8 8 ) \mathrm{V}
$$
D. $$
\beta_{\mathrm{m i n}}=3 0^{\circ}
$$
$$
U_{\mathrm{e}}=( 9 8 7. 6 5 {\sim} 1 4 9 0. 3 0 ) \mathrm{V}
$$
E. $$
\beta_{\mathrm{m i n}}=2 0^{\circ}
$$
$$
U_{\mathrm{e}}=( 9 2 3. 4 8 {\sim} 1 4 5 3. 7 8 ) \mathrm{V}
$$
F. $$
\beta_{\mathrm{m i n}}=7 5^{\circ}
$$
$$
U_{\mathrm{e}}=( 1 2 0 3. 0 0 {\sim} 1 7 2 5. 4 5 ) \mathrm{V}
$$
G. $$
\beta_{\mathrm{m i n}}=5 0^{\circ}
$$
$$
U_{\mathrm{e}}=( 1 0 2 3. 6 9 {\sim} 1 5 3 6. 0 4 ) \mathrm{V}
$$
H. $$
\beta_{\mathrm{m i n}}=5 5^{\circ}
$$
$$
U_{\mathrm{e}}=( 1 0 9 8. 5 0 {\sim} 1 5 9 2. 4 1 ) \mathrm{V}
$$
I. $$
\beta_{\mathrm{m i n}}=7 0^{\circ}
$$
$$
U_{\mathrm{e}}=( 1 1 4 1. 3 3 {\sim} 1 6 5 5. 7 2 ) \mathrm{V}
$$
J. $$
\beta_{\mathrm{m i n}}=8 5^{\circ}
$$
$$
U_{\mathrm{e}}=( 1 2 3 7. 8 8 {\sim} 1 7 8 9. 3 6 ) \mathrm{V}
$$
Answer: A
Given that there are 30 cars randomly distributed along a 6 km long road, find the probability that there are at least 4 cars in any 500 m segment of the road is ().

Options:
A. 0.317
B. 0.487
C. 0.182
D. 0.289
E. 0.244
F. 0.456
G. 0.201
H. 0.374
I. 0.159
J. 0.138
Answer: E
A patient came to the clinic due to diarrhea and abdominal pain for the past three days, self-reporting a sense of urgency and incomplete evacuation, with blood in the stool, suspected to be dysentery. What is the main pathogenic substance of Shigella dysenteriae?

Options:
A. Cytotoxin
B. Neurotoxin
C. Endotoxin
D. Lipid A
E. Sporophyte
F. Exotoxin
G. Enterovirus
H. Glycoprotein
I. Hemotoxin
J. Mycotoxin
Answer: C
Of the given, which protein filament is 50 to 55% in the muscle?

Options:
A. Desmin
B. Troponin
C. Plectin
D. Dystrophin
E. Actin
F. Myosin
G. Lamin
H. Tropomyosin
I. Titin
J. Nebulin
Answer: F
A certain $\mathrm{CH_{4}}$ gas storage tank has a volume of 1000 m³ and can withstand a pressure of 103 kPa. If the highest temperature in summer is 41°C and the lowest temperature in winter is -25°C, by how many kilograms does the maximum storage limit of $\mathrm{CH_{4}}$ differ between these two temperatures?

Options:
A. $$ 1 6 8. 0 \ \mathrm{k g}
$$
B. $$ 1 7 2. 0 \ \mathrm{k g}
$$
C. $$ 1 5 6. 0 \ \mathrm{k g}
$$
D. $$ 1 7 0. 0 \ \mathrm{k g}
$$
E. $$ 1 5 8. 0 \ \mathrm{k g}
$$
F. $$ 1 6 6. 0 \ \mathrm{k g}
$$
G. $$ 1 8 2. 0 \ \mathrm{k g}
$$
H. $$ 1 7 5. 0 \ \mathrm{k g}
$$
I. $$ 1 6 3. 0 \ \mathrm{k g}
$$
J. $$ 1 6 5. 0 \ \mathrm{k g}
$$
Answer: A
The kinetic energy of a certain extranuclear electron is $13.6 \mathrm{~eV}$. What is the wavelength of the de Broglie wave of this electron?

Options:
A. $$
4 4 4 \mathrm{~ p m}
$$
B. $$
1 2 0 \mathrm{~ p m}
$$
C. $$
3 0 0 \mathrm{~ p m}
$$
D. $$
5 0 0 \mathrm{~ p m}
$$
E. $$
6 0 0 \mathrm{~ p m}
$$
F. $$
1 8 0 \mathrm{~ p m}
$$
G. $$
2 5 0 \mathrm{~ p m}
$$
H. $$
4 5 0 \mathrm{~ p m}
$$
I. $$
2 0 0 \mathrm{~ p m}
$$
J. $$
3 3 1 \mathrm{~ p m}
$$
Answer: J
At a certain temperature, under 100 kPa, the reaction
$$
2 \mathrm{NO}_{2} \rightleftharpoons \mathrm{N}_{2} \mathrm{O}_{4}
$$
has a standard equilibrium constant $K^{\ominus}=3.06$. What is the equilibrium conversion rate of $\mathrm{NO}_{2}$?

Options:
A. $$
3 5. 5\%
$$
B. $$
8 5. 0\%
$$
C. $$
6 7. 2\%
$$
D. $$
4 5. 9\%
$$
E. $$
9 0. 4\%
$$
F. $$
5 8. 8\%
$$
G. $$
7 8. 3\%
$$
H. $$
7 2. 5\%
$$
I. $$
6 0. 0\%
$$
J. $$
8 0. 1\%
$$
Answer: H
At 1.013×10° Pa, the boiling point of water is 373 K. If the heat of vaporization of water is $44.0 \mathrm{~kJ \cdot mol}^{-1}$, what is the functional relationship between the saturation vapor pressure $p$ of water and the thermodynamic temperature $T$?

Options:
A. $$
p \left( \mathrm{~ H_{2} ~ 0 ~} \right) / \left( \mathrm{~ 1 0^{3} ~ P a ~} \right)=1. 8 7 {\times} 1 0^{5} \mathrm{e}^{-\frac{\mathrm{5~ 6 1 0}} {\mathrm{T/K}}}
$$
B. $$
p \left( \mathrm{~ H_{2} ~ 0 ~} \right) / \left( \mathrm{~ 1 0^{4} ~ P a ~} \right)=1. 3 0 {\times} 1 0^{7} \mathrm{e}^{-\frac{\mathrm{4~ 8 5 2}} {\mathrm{T/K}}}
$$
C. $$
p \left( \mathrm{~ H_{2} ~ 0 ~} \right) / \left( \mathrm{~ 1 0^{6} ~ P a ~} \right)=1. 4 9 {\times} 1 0^{4} \mathrm{e}^{-\frac{\mathrm{5~ 8 7 2}} {\mathrm{T/K}}}
$$
D. $$
p \left( \mathrm{~ H_{2} ~ 0 ~} \right) / \left( \mathrm{~ 1 0^{5} ~ P a ~} \right)=1. 4 6 {\times} 1 0^{6} \mathrm{e}^{-\frac{\mathrm{5~ 2 9 2}} {\mathrm{T/K}}}
$$
E. $$
p \left( \mathrm{~ H_{2} ~ 0 ~} \right) / \left( \mathrm{~ 1 0^{5} ~ P a ~} \right)=1. 6 7 {\times} 1 0^{8} \mathrm{e}^{-\frac{\mathrm{4~ 9 1 0}} {\mathrm{T/K}}}
$$
F. $$
p \left( \mathrm{~ H_{2} ~ 0 ~} \right) / \left( \mathrm{~ 1 0^{5} ~ P a ~} \right)=1. 3 9 {\times} 1 0^{5} \mathrm{e}^{-\frac{\mathrm{5~ 3 2 9}} {\mathrm{T/K}}}
$$
G. $$
p \left( \mathrm{~ H_{2} ~ 0 ~} \right) / \left( \mathrm{~ 1 0^{5} ~ P a ~} \right)=1. 4 2 {\times} 1 0^{6} \mathrm{e}^{-\frac{\mathrm{5~ 6 4 7}} {\mathrm{T/K}}}
$$
H. $$
p \left( \mathrm{~ H_{2} ~ 0 ~} \right) / \left( \mathrm{~ 1 0^{5} ~ P a ~} \right)=1. 7 3 {\times} 1 0^{7} \mathrm{e}^{-\frac{\mathrm{4~ 7 5 0}} {\mathrm{T/K}}}
$$
I. $$
p \left( \mathrm{~ H_{2} ~ 0 ~} \right) / \left( \mathrm{~ 1 0^{5} ~ P a ~} \right)=2. 0 5 {\times} 1 0^{6} \mathrm{e}^{-\frac{\mathrm{4~ 3 9 2}} {\mathrm{T/K}}}
$$
J. $$
p \left( \mathrm{~ H_{2} ~ 0 ~} \right) / \left( \mathrm{~ 1 0^{5} ~ P a ~} \right)=1. 5 6 {\times} 1 0^{6} \mathrm{e}^{-\frac{\mathrm{5~ 0 2 3}} {\mathrm{T/K}}}
$$
Answer: D
In the solution, the initial concentrations of $\mathrm{Cu}^{2+}$ and $\mathrm{NH_{3} \cdot H_{2}O}$ are 0.20 mol·$\mathrm{dm}^{-3}$ and 1.0 mol·$\mathrm{dm}^{-3}$, respectively. Given that the $K_{\mathrm{Steady state}}^{\ominus}$ of $\left[\mathrm{Cu(NH_{3})_{4}}\right]^{2+}$ is $2.1 \times 10^{13}$, what is the concentration of $\mathrm{Cu}^{2+}$ remaining in the solution at equilibrium?

Options:
A. $$
7. 0 \times1 0^{-1 3} \mathrm{~ m o l ~ \cdot~ d m}^{-3}
$$
B. $$
4. 0 \times1 0^{-1 1} \mathrm{~ m o l ~ \cdot~ d m}^{-3}
$$
C. $$
9. 0 \times1 0^{-1 2} \mathrm{~ m o l ~ \cdot~ d m}^{-3}
$$
D. $$
3. 0 \times1 0^{-1 2} \mathrm{~ m o l ~ \cdot~ d m}^{-3}
$$
E. $$
1. 0 \times1 0^{-1 2} \mathrm{~ m o l ~ \cdot~ d m}^{-3}
$$
F. $$
8. 0 \times1 0^{-1 3} \mathrm{~ m o l ~ \cdot~ d m}^{-3}
$$
G. $$
5. 0 \times1 0^{-1 2} \mathrm{~ m o l ~ \cdot~ d m}^{-3}
$$
H. $$
6. 0 \times1 0^{-1 2} \mathrm{~ m o l ~ \cdot~ d m}^{-3}
$$
I. $$
7. 0 \times1 0^{-1 1} \mathrm{~ m o l ~ \cdot~ d m}^{-3}
$$
J. $$
2. 0 \times1 0^{-1 1} \mathrm{~ m o l ~ \cdot~ d m}^{-3}
$$
Answer: H
In a mixed solution of Ba²⁺ and Sr²⁺, both at a concentration of 0.10 mol·dm⁻³, a very dilute Na₂SO₄ solution is added dropwise to the mixture. It is known that the solubility product $K_{\mathrm{sp}}^{\ominus}$ of BaSO₄ is 1.1 × 10⁻¹⁰, and that of SrSO₄ is 3.4 × 10⁻⁷. When 99.99% of Ba²⁺ has precipitated as BaSO₄, what percentage of Sr²⁺ has converted to SrSO₄?

Options:
A. $$
6 9 \%
$$
B. $$
4 9 \%
$$
C. $$
7 5 \%
$$
D. $$
8 3 \%
$$
E. $$
8 8 \%
$$
F. $$
5 8 \%
$$
G. $$
6 1 \%
$$
H. $$
9 1 \%
$$
I. $$
7 2 \%
$$
J. $$
7 0 \%
$$
Answer: A
On $\mathbf{T}_{2} \mathbf{W} \mathbf{I}$, a low-signal ring appears in the subacute and chronic phases of hematoma because____.

Options:
A. Iron from degrading red blood cells forms insoluble ferritin in macrophages.
B. Inflammatory cytokines trigger lymphocyte infiltration around the hemorrhage site.
C. Reactive gliosis develops, encapsulating the hematoma with fibrous tissue.
D. Macrophages surrounding the hematoma phagocytize a large amount of hemosiderin.
E. White matter tracts realign themselves altering the MRI visibility of the lesion.
F. Edema causes compression, leading to disrupted tissue architecture and signal loss.
G. Protein degradation occurs, releasing globin chains from hemoglobin complexes.
H. Angiogenesis results in new blood vessels altering the signal intensity pattern.
I. Calcification processes occur, leading to a dense shell surrounding the hematoma.
J. Blood-brain barrier disruption causes excess fluid accumulation around hemosiderin.
Answer: D
A young child presented with a yellow light reflex in one eye and underwent an orbital CT scan: a soft tissue mass was observed at the posterior pole inside one eye socket, with large irregular calcifications, and the adjacent optic nerve was significantly thickened. The primary consideration is ().

Options:
A. Retinoblastoma
B. Choroidal hemangioma
C. Optic glioma
D. Orbital cellulitis
E. Congenital cataract
F. Uveal metastasis
G. Coats' disease
H. Ocular melanoma
I. Persistent fetal vasculature
J. Juvenile xanthogranuloma
Answer: A
The glottic laryngeal cancer CT indicates subglottic invasion when it extends downward more than 5mm beyond which of the following structures?

Options:
A. Superior thyroid notch
B. Lamina of thyroid cartilage
C. Cricoid cartilage
D. Median cricothyroid ligament
E. Hyoid bone
F. Arytenoid vocal process
G. Thyroid cartilage
H. Petiole of the epiglottis
I. Epiglottic cartilage
J. Cricothyroid joint
Answer: F
Right hilum angle is the angle between which two structures?

Options:
A. Right middle lobe bronchial artery and right lung apical segment
B. Right hilum lymph nodes and right pulmonary vein branch
C. Right lower lobe segmental vein and right main venous trunk
D. Right pulmonary artery trunk and right anterior descending artery
E. Right main bronchus and right lower lobe pulmonary veins
F. Right pneumothorax cavity and right main bronchus bifurcation
G. Right upper lobe posteroinferior venous trunk and right lower lobe pulmonary artery
H. Right superior pulmonary vein and azygos vein branch
I. Right oblique fissure and horizontal fissure junction
J. Right lower lobe bronchi and right pulmonary ligament insertion
Answer: G
The X-ray characteristics of the cavities formed by peripheral lung cancer are ().

Options:
A. Thin wall, eccentricity, smooth outer wall surface, noticeable fluid level
B. Thin wall, uniformity, irregular outer wall surface, ambiguous fluid level
C. Thick wall, irregularity, smooth inner wall surface, distinct fluid level
D. Thin wall, symmetry, smooth inner wall surface, clear fluid level
E. Thick wall, uniformity, consistent inner surface texture, evident fluid level
F. Thin wall, asymmetry, uneven outer wall surface, obscure fluid level
G. Thick wall, symmetry, even inner surface texture, definite fluid level
H. Thick wall, eccentricity, uneven inner wall surface, no obvious fluid level
I. Thick wall, central position, even outer wall surface, distinct fluid level
J. Thin wall, centrality, rough inner surface texture, uniform fluid level
Answer: H
Regarding the MRI diagnosis of mediastinal tumors, which of the following statements is correct?

Options:
A. The identification of thymic tissue is beyond the capabilities of MRI.
B. The relationship of lesions to the aorta cannot be established by MRI.
C. The status of lymph nodes cannot be assessed with MRI techniques.
D. The presence of calcifications is best seen with MRI imaging alone.
E. The vascular invasion by neoplasms is not visible on MRI images.
F. The relationship between the posterior mediastinal neurogenic tumor and the spinal canal is well demonstrated.
G. Mediastinal fat is indistinguishable from other tissues on MRI scans.
H. Only anterior mediastinal masses can be evaluated using MRI scans.
I. MRI is unable to differentiate solid and cystic components in tumors.
J. MRI has no role in the evaluation of the posterior mediastinum.
Answer: F
The X-ray findings of constrictive pericarditis include: ① Superior vena cava dilation; ② Pulmonary congestion; ③ Interstitial pulmonary edema; ④ Right atrial enlargement; ⑤ Left atrial enlargement. The one that reflects the manifestation of left ventricular constriction is ().

Options:
A. ①③④
B. ②③④
C. ①③⑤
D. ①②④
E. ①②③
F. ①②⑤
G. ②④⑤
H. ①④⑤
I. ②③⑤
J. ③④⑤
Answer: I
A 44-year-old male. T1-weighted images show slightly high signal small nodules evenly distributed throughout the liver with a diameter of 0.5-1.0 cm. On T2-weighted images, the nodules display slightly low signals, with the septal signals opposite to the nodule signals. Enhanced scanning reveals that the nodules do not enhance significantly. The most likely diagnosis is ____.

Options:
A. Hepatic hemangiomas with atypia
B. Hepatocellular adenoma cluster
C. Multiple liver lipomas
D. Portal vein thrombosis lesions
E. Focal nodular hyperplasia
F. Cholangiocarcinoma presentation
G. Metastatic liver disease
H. Adenomatous liver hyperplasia
I. Nodular cirrhosis of the liver
J. Liver tuberculomas
Answer: I
Given a charged body with a radius of $a$ and a volume charge density $\rho = \rho_{0} [ 1 - ( R^{2} / a^{2} )]$, it is surrounded by a concentric conducting spherical shell with an inner radius of $b$ ($b > a$) and an outer radius of $c$. Find the electric potential at each point in space.

Options:
A. $$
V_{3} ( R )=\frac{2 \rho_{0} b^{3}} {1 5 \varepsilon_{0} R^2}a_R
$$
B. $$
V_{3} ( R )=\frac{2 \rho_{0} a^{3}} {3 5 \varepsilon_{0} R^2}a_R
$$
C. $$
V_{3} ( R )=\frac{3 \rho_{0} a^{2}} {1 5 \varepsilon_{0} R^2}a_R
$$
D. $$
V_{3} ( R )=\frac{2 \rho_{0} a^{3}} {2 5 \varepsilon_{0} R^2}a_R
$$
E. $$
V_{3} ( R )=\frac{6 \rho_{0} a^{3}} {1 5 \varepsilon_{0} R^2}a_R
$$
F. $$
V_{3} ( R )=\frac{\rho_{0} a^{4}} {1 5 \varepsilon_{0} R^2}a_R
$$
G. $$
V_{3} ( R )=\frac{5 \rho_{0} a^{2}} {1 5 \varepsilon_{0} R^2}a_R
$$
H. $$
V_{3} ( R )=\frac{\rho_{0} b^{3}} {1 5 \varepsilon_{0} R^2}a_R
$$
I. $$
V_{3} ( R )=\frac{4 \rho_{0} a^{3}} {1 5 \varepsilon_{0} R^2}a_R
$$
J. $$
V_{3} ( R )=\frac{2 \rho_{0} a^{3}} {1 5 \varepsilon_{0} R^2}a_R
$$
Answer: J