MikaStars39/nano-eval huggingface dataset:
A capacitor with a capacitance of 10 pF is charged to 100 V and then discharges through a 100-ohm resistor and a 0.4 H inductor in series. What oscillation state is this RLC circuit in? To make it critically damped, how much additional capacitance should be connected in series or parallel?

Options:
A. Under Damping Condition, 250 μF
B. Parallel Resonance Wave, 200 μF
C. Series Resonance State, 150 μF
D. Series Resonance Form, 100 μF
E. Parallel Dampening Set, 500 μF
F. Over Resonant Pathway, 700 μF
G. Non-Resonant Setting, 350 μF
H. Critical Damping Mode, 300 μF
I. Under Resonant Mode, 600 μF
J. Over Damping System, 400 μF
Answer: C
To connect a light bulb labeled "120 V, 60 W" in series with a pure inductance to a 50 Hz, 220 V power supply, what should the self-inductance coefficient of the pure inductor be to ensure the bulb operates normally?

Options:
A. $$
1. 1 7 \mathrm{~ H}
$$
B. $$
1. 9 8 \mathrm{~ H}
$$
C. $$
3. 0 1 \mathrm{~ H}
$$
D. $$
0. 8 3 \mathrm{~ H}
$$
E. $$
1. 5 3 \mathrm{~ H}
$$
F. $$
2. 1 9 \mathrm{~ H}
$$
G. $$
2. 5 7 \mathrm{~ H}
$$
H. $$
1. 2 0 \mathrm{~ H}
$$
I. $$
0. 4 9 \mathrm{~ H}
$$
J. $$
0. 7 5 \mathrm{~ H}
$$
Answer: A
A long straight conductor with a radius of 1.5 cm is encased in a coaxial conducting cylinder with an inner radius of 3.0 cm. What is the electric field strength at a given point when the potential difference between the two is 5000 V?

Options:
A. $$
5. 2 \times1 0^{5} \mathrm{V} / \mathrm{m}
$$
B. $$
7. 1 \times1 0^{5} \mathrm{V} / \mathrm{m}
$$
C. $$
6. 4 \times1 0^{5} \mathrm{V} / \mathrm{m}
$$
D. $$
3. 6 \times1 0^{5} \mathrm{V} / \mathrm{m}
$$
E. $$
2. 9 \times1 0^{5} \mathrm{V} / \mathrm{m}
$$
F. $$
3. 8 \times1 0^{5} \mathrm{V} / \mathrm{m}
$$
G. $$
6. 8 \times1 0^{5} \mathrm{V} / \mathrm{m}
$$
H. $$
4. 8 \times1 0^{5} \mathrm{V} / \mathrm{m}
$$
I. $$
5. 6 \times1 0^{5} \mathrm{V} / \mathrm{m}
$$
J. $$
2. 5 \times1 0^{5} \mathrm{V} / \mathrm{m}
$$
Answer: H
Using ferromagnetic materials with high magnetic permeability, generating a magnetic field of $B = 5000 \, \mathrm{Gs}$ in a laboratory is not difficult. To produce an electric field with an energy density equal to this value, what should the electric field intensity $E$ be?

Options:
A. $$
4. 5 \times1 0^{7} \mathrm{V} / \mathrm{cm}
$$
B. $$
8. 9 \times1 0^{7} \mathrm{V} / \mathrm{m}
$$
C. $$
5. 6 \times1 0^{8} \mathrm{V} / \mathrm{cm}
$$
D. $$
1. 5 \times1 0^{8} \mathrm{V} / \mathrm{m}
$$
E. $$
6. 1 \times1 0^{8} \mathrm{V} / \mathrm{cm}
$$
F. $$
3. 2 \times1 0^{9} \mathrm{V} / \mathrm{m}
$$
G. $$
1. 0 \times1 0^{6} \mathrm{V} / \mathrm{cm}
$$
H. $$
7. 0 \times1 0^{5} \mathrm{V} / \mathrm{m}
$$
I. $$
9. 8 \times1 0^{6} \mathrm{V} / \mathrm{m}
$$
J. $$
2. 3 \times1 0^{7} \mathrm{V} / \mathrm{m}
$$
Answer: D
On activation of the MK 79 MOD 0 signal kit, how far is the star propelled?

Options:
A. The luminary descends into obscurity somewhere between 350 and 750 feet
B. The star is propelled laterally to a distance of between 200 and 600 feet
C. The star is propelled backward to a range of between 150 and 450 feet
D. The star is propelled downward to a depth of between 300 and 700 feet
E. The star ascends to a peak elevation extending beyond between 500 and 1000 feet
F. The star is launched spiraling toward a mark at between 600 and 900 feet
G. The star is propelled upward to a height of between 250 and 650 feet
H. The flare reaches maximum brightness in a span of between 400 and 800 feet
I. The projectile reaches an altitude of no more than between 50 and 150 feet
J. The star disburses in a radius expanding out to between 100 and 300 feet
Answer: G
The MK 58 MOD 1 marine location marker was designed for use under what conditions?

Options:
A. It is designed for clear weather use in any condition requiring a short-lasting visual reference marker on the ocean's surface
B. It is designed for foggy conditions in mountainous regions needing extended light signals for mountain lake marking
C. It is designed for dawn or twilight use in specific situations demanding quick smoke visual aid on river surfaces
D. It is designed for sunlight hours during peacetime exercises calling for immediate smoke effects on seashore zones
E. It is designed for civilian rescue only in predictable weather calling for elongated smoke effects in closed aquatic spaces
F. It is designed for overcast days in stormy conditions needing a transient smoke and light indicator on ocean surfaces
G. It is designed for indoor simulation during exercises necessitating a fast-acting visual cue on water containers
H. It is designed for educational purposes in land environments requiring a prolonged smoky reference point in dry areas
I. It is designed for day or night use in any condition calling for a long burning smoke and flame reference point marking on the oceans surface
J. It is designed for night-time use in calm conditions needing a brief burning reference point signaling on the lake's surface
Answer: I
Before loading a signal into a MK 31 MOD 0 signal projector, you should first take what action?

Options:
A. Wipe the signal with a cleaning cloth
B. Ensure the safety pin is removed
C. Make sure the signal projector is cocked
D. Test the signal in a different projector
E. Disassemble the signal projector completely
F. Recharge the projector's power source
G. Verify the expiration date of the signal
H. Calibrate the signal's frequency settings
I. Confirm the signal is fully armed
J. Align the signal with the firing chamber
Answer: C
What are the two major elements of the MJU-68/B infrared countermeasure flares?

Options:
A. Power source & emission device
B. Flare casing & power adapter
C. Decoy unit & ignition tube
D. Propellant system & decoy unit
E. Flare assembly & igniter assembly
F. Flare core & igniter module
G. Ignition capsule & casing module
H. Ignition system & flare adapter
I. Decoy mechanism & igniter switch
J. Signal emitter & flare module
Answer: E
Pyrotechnic hazards are frequently increased by which of the following factors?

Options:
A. Type of container
B. Storage practices
C. Load intensity
D. Brand reputation
E. Location of use
F. Method of ignition
G. Weather conditions
H. Age of pyrotechnic
I. Ambient temperature
J. Length of usage
Answer: H
To establish an initial contact point for a continued submarine search, which of the following means should be used?

Options:
A. underwater sonar
B. buoy deployment
C. smoke & flame
D. deep sea markers
E. drone surveillance
F. surface radars
G. sonar & lasers
H. sonar beacons
I. magnetic fields
J. thermal imaging
Answer: C
As the first candle nears burnout in a MK 58 marine location marker, the second candle is ignited by what means?

Options:
A. Delayed mechanical linkage
B. Electrical spark gap
C. Water-activated igniter
D. Flame-sensitive element
E. Magnet-induced ignition
F. Chemical reaction fuse
G. Pressure-sensitive switch
H. Proximity heat trigger
I. Air pressure mechanism
J. Transfer time fuze
Answer: J
(a - 9 pts) A candle has a power in the visual band of -3 Watts. When this candle is placed at a distance of 3 km it has the same apparent brightness as a certain star. Assume that this star has the same luminosity as the Sun in the visual band ( $(-1 0^{2 6}$ Watts). How far away is the star?

Options:
A. $$d= 0. 4 5 ~p c$$
B. $$d= 2. 5 0 ~p c$$
C. $$d= 2. 0 0 ~p c$$
D. $$d= 0. 5 6 ~p c$$
E. $$d= 0. 3 5 ~p c$$
F. $$d= 0. 9 0 ~p c$$
G. $$d= 1. 5 0 ~p c$$
H. $$d= 0. 7 5 ~p c$$
I. $$d= 1. 0 0 ~p c$$
J. $$d= 1. 2 0 ~p c$$
Answer: D
What is the spherical excess, if the area of the triangle is given as 32sq. m with a radius of 65m?

Options:
A. 1640.24 m
B. 1500.42 m
C. 1526.24 m
D. 1652.24 m
E. 1550.24 m
F. 1562.42 m
G. 1600.42 m
H. 1602.24 m
I. 1562.24 m
J. 1662.42 m
Answer: I
Suppose air molecules have a collision cross section of $1 0^{-1 6} \mathrm{c m^{2}}$. If the (number) density of air molecules is $1 0^{1 9} \mathrm{~ c m^{-3} ~}$, what is the collision mean free path?

Options:
A. $$1 0^{-3} \mathrm{c m}$$
B. $$1 0^{0} \mathrm{c m}$$
C. $$1 0^{-5} \mathrm{c m}$$
D. $$1 0^{-1} \mathrm{c m}$$
E. $$1 0^{-4} \mathrm{c m}$$
F. $$1 0^{-8} \mathrm{c m}$$
G. $$1 0^{-9} \mathrm{c m}$$
H. $$1 0^{-2} \mathrm{c m}$$
I. $$1 0^{-7} \mathrm{c m}$$
J. $$1 0^{-6} \mathrm{c m}$$
Answer: A
Take the total energy (potential plus thermal) of the Sun to be given by the simple expression:
$$E \simeq-\frac{G M^{2}} {R}$$
where $M$ and $R$ are the mass and radius, respectively. Suppose that the energy generation in the Sun was suddenly turned off and the Sun began to slowly contract. During this contraction its mass, $M$, would remain constant and, to a fair approximation, its surface temperature would also remain constant at $\sim5 8 0 0$ K. Assume that the total energy of the Sun is always given by the above expression, even as $R$ gets smaller. Write down a simple (differential) equation relating the power radiated at Sun's surface with the change in its total energy (using the above expression). Integrate this equation to find the time (in years) for the Sun to shrink to $1 / 2$ its present radius.

Options:
A. 65 hundred centuries
B. 50 trillion hours
C. 72 megayears
D. 75 million years
E. 60 annum epochs
F. 85 billion minutes
G. 80 billion seconds
H. 70 zillion months
I. 77 million weeks
J. 90 thousand decades
Answer: D
The orbits of several stars have been measured orbiting the massive black hole near the center of our Galaxy. One of them has an orbital period of 15 years, and the orbital radius is 0.12 seconds of arc (as seen from the Earth). Take the distance to the Galactic center to be 8 kpc. Compute the mass of the black hole, starting from $F=m a$. Express your answer in units of the Sun's mass $( M_{\odot} )$. (Assume that Newton's law of gravity is applicable for orbits sufficiently far from a black hole and that the orbiting star satisfies this condition.

Options:
A. $$\simeq1. 2 \times1 0^{7} M_{\odot}$$
B. $$\simeq3. 7 \times1 0^{6} M_{\odot}$$
C. $$\simeq6. 3 \times1 0^{6} M_{\odot}$$
D. $$\simeq8. 8 \times1 0^{6} M_{\odot}$$
E. $$\simeq4. 2 \times1 0^{6} M_{\odot}$$
F. $$\simeq2. 5 \times1 0^{6} M_{\odot}$$
G. $$\simeq1. 9 \times1 0^{6} M_{\odot}$$
H. $$\simeq3. 0 \times1 0^{6} M_{\odot}$$
I. $$\simeq5. 0 \times1 0^{6} M_{\odot}$$
J. $$\simeq7. 5 \times1 0^{6} M_{\odot}$$
Answer: B
In a certain region in 2006, the total rural economic income was composed as follows: agriculture income 49%; fishery income 1%; industrial income 12%; construction income 7.2%; transportation income 8.3%; tourism income 5.5%; service industry income 4%; and other incomes 3%. According to the horizontal division of labor in rural economy, what is the proportion of the primary industry in rural areas?

Options:
A. 62%
B. 58%
C. 61%
D. 57%
E. 65%
F. 60%
G. 45%
H. 63%
I. 66%
J. 64%
Answer: F
When intramuscular EMG is required to look into the electrical activities of deeper or overlaid muscles, which electrodes are used?

Options:
A. plate shape electrodes
B. short needle electrodes
C. thin thread electrodes
D. dermal strip electrodes
E. fine wire electrodes
F. wide band electrodes
G. flexible loop electrodes
H. circular patch electrodes
I. surface electrodes
J. flat sheet electrodes
Answer: E
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 would be the resonance frequency at 1.5T?

Options:
A. γₑ = 6.0 x 10¹⁰ Hz / T. At 1.5 T, v = 9.0 GHz
B. γₑ = 4.5 x 10¹⁰ Hz / T. At 1.5 T, v = 67.5 GHz
C. γₑ = 9.0 x 10¹⁰ Hz / T. At 1.5 T, v = 13.5 GHz
D. γₑ = 8.0 x 10¹⁰ Hz / T. At 1.5 T, v = 120.0 GHz
E. γₑ = 1.8 x 10¹⁰ Hz / T. At 1.5 T, v = 27.0 GHz
F. γₑ = 3.5 x 10¹⁰ Hz / T. At 1.5 T, v = 52.5 GHz
G. γₑ = 7.0 x 10¹⁰ Hz / T. At 1.5 T, v = 10.5 GHz
H. γₑ = 5.0 x 10¹⁰ Hz / T. At 1.5 T, v = 75.0 GHz
I. γₑ = 2.8 x 10¹⁰ Hz / T. At 1.5 T, v = 42.0 GHz
J. γₑ = 2.0 x 10¹⁰ Hz / T. At 1.5 T, v = 30.0 GHz
Answer: I
The patient is a 20-year-old male with extensive burns on the back and buttocks. After initial treatment, his condition was tentatively stabilized. Two days after being admitted to the hospital, he suddenly developed symptoms of respiratory distress and loss of consciousness. The first consideration for the possible situation the patient may be experiencing is ( ).

Options:
A. Pulmonary and cerebral fat embolism
B. Severe skeletal muscle breakdown
C. Drug-induced hypoxia
D. Adverse allergic reaction events
E. Acute pulmonary hypertension
F. Sudden heart failure syndrome
G. Infectious encephalitis
H. Neurogenic shock episode
I. Acute respiratory distress syndrome
J. Profound systemic infection
Answer: A
Male child, 1 year and 5 months old, admitted due to "fever accompanied by vomiting for 8 days, and one seizure." Physical examination: body temperature 39.5°C, pulse 117 beats/min, respiration 37 breaths/min, blood pressure 80/70 mmHg. Routine blood tests: hemoglobin 118 g/L, white blood cell count $24.6 \times 10^9/L$, neutrophils 87%. Stool test: negative. Cerebrospinal fluid is cloudy, white blood cell count $8.6 \times 10^6/L$, polymorphonuclear cells 84%. The nature of the lesion is().

Options:
A. Focal infiltration
B. Meningococcal colonization
C. Vasogenic edema
D. Subdural empyema
E. Periosteal abscess
F. Lymphatic dysplasia
G. Cavernous hemangioma
H. Nodal sclerosis
I. Epidermal phytosis
J. Surface suppuration
Answer: J
In a certain PAM baseband transmission system, disregarding noise, the output signal of the receiving filter is
$y ( t )=\\sum_{n=0}^{\\infty} b_{n} h ( t-n T_{\\mathrm{s}} )$
where $\\{b_{0}, b_{1}, b_{2}, \\cdots\\}$ is the amplitude sequence transmitted by the PAM system. Given the symbol interval $T_{s}=0. 5$, the overall impulse response of the system is
$h ( t )=\\operatorname{s i n c} ( t ) \\cdot{\\frac{\\operatorname{c o s} \\pi t} {1-4 t^{2}}}$
Let \( $h_m = h(mT_s)$ \), \( $y_m = y(mT_s)$ \). Find the values of \( $h_0, h_1, h_{-1}, h_2, h_{-2}$ \) and the expressions for $y_{0}, y_{1}, y_{2}$.

Options:
A. $$
\begin{array} {l} {{h_{0}=1, ~ h_{\pm1}=\frac{1} {3}, ~ h_{\pm2}=\frac{1} {3}}} \\ {{y_{0}=b_{0}+\frac{b_{1}} {3}, ~ ~ y_{1}=b_{1}+\frac{b_{0}+b_{2}} {3}, ~ ~ y_{2}=b_{2}+\frac{b_{1}+b_{3}} {3}}} \\ \end{array}
$$
B. $$
\begin{array} {l} {{h_{0}=1, ~ h_{\pm1}=\frac{1} {6}, ~ h_{\pm2}=0}} \\ {{y_{0}=b_{0}+b_{2}, ~ ~ y_{1}=b_{1}+\frac{b_{0}+b_{2}} {2}, ~ ~ y_{2}=b_{2}+\frac{b_{1}+b_{4}} {2}}} \\ \end{array}
$$
C. $$
\begin{array} {l} {{h_{0}=2, ~ h_{\pm1}=\frac{1} {2}, ~ h_{\pm2}=0.1}} \\ {{y_{0}=b_{0}+b_{1}, ~ ~ y_{1}=b_{1}+\frac{b_{0}+b_{2}} {2}, ~ ~ y_{2}=b_{2}+\frac{b_{1}+b_{3}} {4}}} \\ \end{array}
$$
D. $$
\begin{array} {l} {{h_{0}=\frac{5} {8}, ~ h_{\pm1}=\frac{1} {4}, ~ h_{\pm2}=0}} \\ {{y_{0}=b_{0}+\frac{1} {4}b_{1}, ~ ~ y_{1}=b_{1}+\frac{b_{0}+b_{2}} {2}, ~ ~ y_{2}=b_{2}+\frac{b_{1}+b_{3}} {5}}} \\ \end{array}
$$
E. $$
\begin{array} {l} {{h_{0}=1, ~ h_{\pm1}=\frac{1} {2}, ~ h_{\pm2}=0}} \\ {{y_{0}=b_{0}+\frac{1} {2} b_{1}, ~ ~ y_{1}=b_{1}+\frac{b_{0}+b_{2}} {2}, ~ ~ y_{2}=b_{2}+\frac{b_{1}+b_{3}} {2}}} \\ \end{array}
$$
F. $$
\begin{array} {l} {{h_{0}=\frac{1} {3}, ~ h_{\pm1}=2, ~ h_{\pm2}=0}} \\ {{y_{0}=b_{0}+\frac{1} {4}b_{3}, ~ ~ y_{1}=b_{1}+\frac{b_{0}+b_{2}} {4}, ~ ~ y_{2}=b_{2}+\frac{b_{1}+b_{3}} {5}}} \\ \end{array}
$$
G. $$
\begin{array} {l} {{h_{0}=1, ~ h_{\pm1}=0, ~ h_{\pm2}=\frac{1} {3}}} \\ {{y_{0}=b_{0} + b_{1}, ~ ~ y_{1}=b_{1}+\frac{b_{0}+b_{2}} {3}, ~ ~ y_{2}=b_{2}+\frac{b_{1}+b_{3}} {3}}} \\ \end{array}
$$
H. $$
\begin{array} {l} {{h_{0}=\frac{3} {2}, ~ h_{\pm1}=\frac{1} {4}, ~ h_{\pm2}=0}} \\ {{y_{0}=b_{0}+b_{1}, ~ ~ y_{1}=b_{1}+\frac{b_{0}+b_{2}} {4}, ~ ~ y_{2}=b_{2}+\frac{b_{1}+b_{3}} {4}}} \\ \end{array}
$$
I. $$
\begin{array} {l} {{h_{0}=0.7, ~ h_{\pm1}=\frac{1} {4}, ~ h_{\pm2}=\frac{1} {5}}} \\ {{y_{0}=b_{0}+\frac{b_{1}} {3}, ~ ~ y_{1}=b_{1}+\frac{b_{0}+b_{2}} {1}, ~ ~ y_{2}=b_{2}+\frac{b_{1}+b_{3}} {6}}} \\ \end{array}
$$
J. $$
\begin{array} {l} {{h_{0}=1.5, ~ h_{\pm1}=0.3, ~ h_{\pm2}=0}} \\ {{y_{0}=b_{0}+\frac{1} {2}b_{2}, ~ ~ y_{1}=b_{1}+\frac{b_{0}+b_{2}} {1}, ~ ~ y_{2}=b_{2}+\frac{b_{1}+b_{4}} {2}}} \\ \end{array}
$$
Answer: E
In a baseband transmission system, the sample value at the sampling time is $y = a + n + i_{\mathrm{m}}$, where $a$ takes values of ±1 with equal probability. $n$ is Gaussian noise with a mean of zero and a variance of $\sigma^{2} = \frac{1}{2}$. $i_{\mathrm{m}}$ is the inter-symbol interference value at the sampling point, taking values from $\{0, -1, +1\}$ with equal probability and is independent of $a$. The decision threshold at the receiving end is $V_{\mathrm{th}} = 0$. If $y \geq V_{\mathrm{th}}$, then $a$ is decided as +1, otherwise $a$ is decided as -1. Determine the average bit error rate of this system.

Options:
A. $$
{\frac{1} {6}} {\bigl[} 1 \!+\! \mathrm{e r f c} {\bigl(} 0 {\bigr)} \!+\! \mathrm{e r f c} {\bigl(} 1 {\bigr)} {\bigr]}
$$
B. $$
{\frac{1} {6}} {\bigl[} 0 \!+\! \mathrm{e r f c} {\bigl(} 1 {\bigr)} \!+\! \mathrm{e r f c} {\bigl(} 2 {\bigr)} {\bigr]}
$$
C. $$
{\frac{1} {5}} {\bigl[} 1 \!+\! \mathrm{e r f c} {\bigl(} 1 {\bigr)} \!+\! \mathrm{e r f c} {\bigl(} 2.5 {\bigr)} {\bigr]}
$$
D. $$
{\frac{1} {8}} {\bigl[} 1 \!+\! \mathrm{e r f c} {\bigl(} 0.5 {\bigr)} \!+\! \mathrm{e r f c} {\bigl(} 3 {\bigr)} {\bigr]}
$$
E. $$
{\frac{1} {3}} {\bigl[} 1 \!+\! \mathrm{e r f c} {\bigl(} 1.5 {\bigr)} \!+\! \mathrm{e r f c} {\bigl(} 2 {\bigr)} {\bigr]}
$$
F. $$
{\frac{1} {6}} {\bigl[} 1 \!+\! \mathrm{e r f c} {\bigl(} 1 {\bigr)} \!+\! \mathrm{e r f c} {\bigl(} 2 {\bigr)} {\bigr]}
$$
G. $$
{\frac{1} {6}} {\bigl[} 1 \!+\! \mathrm{e r f c} {\bigl(} 1.5 {\bigr)} \!+\! \mathrm{e r f c} {\bigl(} 3 {\bigr)} {\bigr]}
$$
H. $$
{\frac{1} {6}} {\bigl[} 2 \!+\! \mathrm{e r f c} {\bigl(} 1 {\bigr)} \!+\! \mathrm{e r f c} {\bigl(} 2 {\bigr)} {\bigr]}
$$
I. $$
{\frac{1} {4}} {\bigl[} 1 \!+\! \mathrm{e r f c} {\bigl(} 1 {\bigr)} \!+\! \mathrm{e r f c} {\bigl(} 2 {\bigr)} {\bigr]}
$$
J. $$
{\frac{1} {6}} {\bigl[} 1 \!+\! \mathrm{e r f c} {\bigl(} 0.5 {\bigr)} \!+\! \mathrm{e r f c} {\bigl(} 2.5 {\bigr)} {\bigr]}
$$
Answer: F
An ideal channel with an average power constraint, affected by additive white Gaussian noise, has a bandwidth of __, and a signal-to-noise ratio (SNR) of 20dB. Find the channel capacity. If the SNR drops to 10dB, determine the required channel bandwidth.

Options:
A. The channel capacity is $7.00 \times 10^{6} \, \text{bit/s}$, with a bandwidth of $1.75 \times 10^{6} \, \text{Hz}$.
B. The channel capacity is $7.35 \times 10^{6} \, \text{bit/s}$, with a bandwidth of $1.95 \times 10^{6} \, \text{Hz}$.
C. The channel capacity is $6.50 \times 10^{6} \, \text{bit/s}$, with a bandwidth of $2.00 \times 10^{6} \, \text{Hz}$.
D. The channel capacity is $5.85 \times 10^{6} \, \text{bit/s}$, with a bandwidth of $2.15 \times 10^{6} \, \text{Hz}$.
E. The channel capacity is $6.65 \times 10^{6} \, \text{bit/s}$, with a bandwidth of $1.92 \times 10^{6} \, \text{Hz}$.
F. The channel capacity is $6.75 \times 10^{6} \, \text{bit/s}$, with a bandwidth of $2.25 \times 10^{6} \, \text{Hz}$.
G. The channel capacity is $8.00 \times 10^{6} \, \text{bit/s}$, with a bandwidth of $1.50 \times 10^{6} \, \text{Hz}$.
H. The channel capacity is $5.00 \times 10^{6} \, \text{bit/s}$, with a bandwidth of $2.50 \times 10^{6} \, \text{Hz}$.
I. The channel capacity is $7.75 \times 10^{6} \, \text{bit/s}$, with a bandwidth of $2.05 \times 10^{6} \, \text{Hz}$.
J. The channel capacity is $6.25 \times 10^{6} \, \text{bit/s}$, with a bandwidth of $2.10 \times 10^{6} \, \text{Hz}$.
Answer: E
For a roll-off factor of $a=1$, the input of a raised cosine roll-off inter-symbol interference-free baseband transmission system is hexadecimal symbols, with a symbol rate of $R_{B}=1200$ Baud. Determine the cut-off frequency of this baseband transmission system, the bandwidth efficiency of the system, and the information transmission rate of the system.

Options:
A. $B=1 1 0 0 \mathrm{H z}$ , $1 \mathrm{B a u d} / \mathrm{H z}$ , $4 4 0 0 \mathrm{b i t} / \mathrm{s}$ .
B. $B=1 8 0 0 \mathrm{H z}$ , $1 \mathrm{B a u d} / \mathrm{H z}$ , $4 6 0 0 \mathrm{b i t} / \mathrm{s}$ .
C. $B=1 0 0 0 \mathrm{H z}$ , $1 \mathrm{B a u d} / \mathrm{H z}$ , $4 0 0 0 \mathrm{b i t} / \mathrm{s}$ .
D. $B=1 3 0 0 \mathrm{H z}$ , $1 \mathrm{B a u d} / \mathrm{H z}$ , $4 2 0 0 \mathrm{b i t} / \mathrm{s}$ .
E. $B=1 5 0 0 \mathrm{H z}$ , $0 . 5 \mathrm{B a u d} / \mathrm{H z}$ , $4 5 0 0 \mathrm{b i t} / \mathrm{s}$ .
F. $B=1 4 0 0 \mathrm{H z}$ , $1 \mathrm{B a u d} / \mathrm{H z}$ , $5 2 0 0 \mathrm{b i t} / \mathrm{s}$ .
G. $B=1 2 0 0 \mathrm{H z}$ , $1 \mathrm{B a u d} / \mathrm{H z}$ , $4 8 0 0 \mathrm{b i t} / \mathrm{s}$ .
H. $B=2 0 0 0 \mathrm{H z}$ , $0 . 5 \mathrm{B a u d} / \mathrm{H z}$ , $5 8 0 0 \mathrm{b i t} / \mathrm{s}$ .
I. $B=1 6 0 0 \mathrm{H z}$ , $1 \mathrm{B a u d} / \mathrm{H z}$ , $5 6 0 0 \mathrm{b i t} / \mathrm{s}$ .
J. $B=1 7 0 0 \mathrm{H z}$ , $1 \mathrm{B a u d} / \mathrm{H z}$ , $5 0 0 0 \mathrm{b i t} / \mathrm{s}$ .
Answer: G
Perform PCM time-division multiplex transmission for 10 channels of analog signals, each with a bandwidth of $0 \sim 4000 \mathrm{Hz}$. The sampling rate is $8000 \mathrm{Hz}$. After sampling, apply 16-level quantization and encode into natural binary code. Calculate the bandwidth required to transmit this time-division multiplexed signal.

Options:
A. $$
3. 2 \times1 0^{5} \mathrm{H z}
$$
B. $$
1. 0 \times1 0^{6} \mathrm{H z}
$$
C. $$
1. 6 \times1 0^{5} \mathrm{H z}
$$
D. $$
7. 8 \times1 0^{4} \mathrm{H z}
$$
E. $$
2. 4 \times1 0^{5} \mathrm{H z}
$$
F. $$
4. 8 \times1 0^{4} \mathrm{H z}
$$
G. $$
9. 6 \times1 0^{4} \mathrm{H z}
$$
H. $$
5. 2 \times1 0^{5} \mathrm{H z}
$$
I. $$
8. 4 \times1 0^{4} \mathrm{H z}
$$
J. $$
5. 0 \times1 0^{5} \mathrm{H z}
$$
Answer: C
Sample a uniformly distributed random simulated signal, quantize it uniformly, and encode it into binary PCM (Pulse Code Modulation) signals, with a quantization signal-to-noise ratio of 42.1442 dB. For each sampling value corresponding to a PCM codeword, add a one-bit synchronization pulse at the end, and then transmit it using a quadrature PAM (Pulse Amplitude Modulation) system with a raised cosine spectrum. The roll-off factor of the raised cosine is \(\alpha = 0.5\). The bandwidth of the transmission channel is 12 kHz. What is the highest frequency component \(f_b\) of the analog signal?

Options:
A. $1kHz$
B. $9kHz$
C. $3kHz$
D. $7kHz$
E. $2kHz$
F. $5kHz$
G. $4kHz$
H. $10kHz$
I. $6kHz$
J. $8kHz$
Answer: E
A certain transmitter has a transmission power of 10 W, a carrier frequency of 900 MHz, a transmission antenna gain \( $G_{\mathrm{T}}=2$ \), and a receiving antenna gain \( $G_{\mathrm{R}}=3$ \). Calculate the output power of the receiver and the path loss at a distance of 10 km from the transmitter in free space.

Options:
A. $$
P_{\mathrm{R}}=R_{\mathrm{T}} G_{\mathrm{T}} G_{\mathrm{R}} \left( \frac{\lambda} {3 \pi d} \right)^{2}=2. \, 5 5 \times1 0^{-1 2} \, \, \, \mathrm{W}
$$
$$
L={\frac{P_{\mathrm{T}}} {P_{\mathrm{R}}}}=5. \, 1 9 \times1 0^{1 1} \, ( \mathrm{~ B I I ~ 1 4 2. ~ 4 3 ~ d B} )
$$
B. $$
P_{\mathrm{R}}=R_{\mathrm{T}} G_{\mathrm{T}} G_{\mathrm{R}} \left( \frac{\lambda} {4 \pi d} \right)^{2}=5. \, 0 7 \times1 0^{-1 1} \, \, \, \mathrm{W}
$$
$$
L={\frac{P_{\mathrm{T}}} {P_{\mathrm{R}}}}=1. \, 9 7 \times1 0^{1 0} \, ( \mathrm{~ B I I ~ 1 0 1. ~ 9 5 ~ d B} )
$$
C. $$
P_{\mathrm{R}}=R_{\mathrm{T}} G_{\mathrm{T}} G_{\mathrm{R}} \left( \frac{\lambda} {4 \pi d} \right)^{2}=1. \, 7 4 \times1 0^{-1 0} \, \, \, \mathrm{W}
$$
$$
L={\frac{P_{\mathrm{T}}} {P_{\mathrm{R}}}}=4. \, 8 1 \times1 0^{9} \, ( \mathrm{~ B I I ~ 9 8. ~ 4 8 ~ d B} )
$$
D. $$
P_{\mathrm{R}}=R_{\mathrm{T}} G_{\mathrm{T}} G_{\mathrm{R}} \left( \frac{\lambda} {5 \pi d} \right)^{2}=8. \, 4 0 \times1 0^{-1 0} \, \, \, \mathrm{W}
$$
$$
L={\frac{P_{\mathrm{T}}} {P_{\mathrm{R}}}}=3. \, 9 8 \times1 0^{9} \, ( \mathrm{~ B I I ~ 9 6. ~ 0 7 ~ d B} )
$$
E. $$
P_{\mathrm{R}}=R_{\mathrm{T}} G_{\mathrm{T}} G_{\mathrm{R}} \left( \frac{\lambda} {4 \pi d} \right)^{2}=2. \, 9 3 \times1 0^{-1 0} \, \, \, \mathrm{W}
$$
$$
L={\frac{P_{\mathrm{T}}} {P_{\mathrm{R}}}}=6. \, 2 9 \times1 0^{9} \, ( \mathrm{~ B I I ~ 9 9. ~ 9 0 ~ d B} )
$$
F. $$
P_{\mathrm{R}}=R_{\mathrm{T}} G_{\mathrm{T}} G_{\mathrm{R}} \left( \frac{\lambda} {3 \pi d} \right)^{2}=6. \, 8 3 \times1 0^{-1 0} \, \, \, \mathrm{W}
$$
$$
L={\frac{P_{\mathrm{T}}} {P_{\mathrm{R}}}}=1. \, 4 6 \times1 0^{1 0} \, ( \mathrm{~ B I I ~ 8 9. ~ 3 5 ~ d B} )
$$
G. $$
P_{\mathrm{R}}=R_{\mathrm{T}} G_{\mathrm{T}} G_{\mathrm{R}} \left( \frac{\lambda} {4 \pi d} \right)^{3}=9. \, 1 1 \times1 0^{-1 1} \, \, \, \mathrm{W}
$$
$$
L={\frac{P_{\mathrm{T}}} {P_{\mathrm{R}}}}=3. \, 6 4 \times1 0^{1 0} \, ( \mathrm{~ B I I ~ 1 0 4. ~ 7 8 ~ d B} )
$$
H. $$
P_{\mathrm{R}}=R_{\mathrm{T}} G_{\mathrm{T}} G_{\mathrm{R}} \left( \frac{\lambda} {4 \pi d} \right)^{1}=3. \, 1 2 \times1 0^{-0 9} \, \, \, \mathrm{W}
$$
$$
L={\frac{P_{\mathrm{T}}} {P_{\mathrm{R}}}}=9. \, 2 4 \times1 0^{9} \, ( \mathrm{~ B I I ~ 9 9. ~ 6 3 ~ d B} )
$$
I. $$
P_{\mathrm{R}}=R_{\mathrm{T}} G_{\mathrm{T}} G_{\mathrm{R}} \left( \frac{\lambda} {4 \pi d} \right)^{2}=4. \, 2 2 \times1 0^{-1 0} \, \, \, \mathrm{W}
$$
$$
L={\frac{P_{\mathrm{T}}} {P_{\mathrm{R}}}}=2. \, 3 7 \times1 0^{1 0} \, ( \mathrm{~ B I I ~ 1 0 3. ~ 7 5 ~ d B} )
$$
J. $$
P_{\mathrm{R}}=R_{\mathrm{T}} G_{\mathrm{T}} G_{\mathrm{R}} \left( \frac{\lambda} {6 \pi d} \right)^{2}=7. \, 9 5 \times1 0^{-1 1} \, \, \, \mathrm{W}
$$
$$
L={\frac{P_{\mathrm{T}}} {P_{\mathrm{R}}}}=2. \, 5 0 \times1 0^{1 0} \, ( \mathrm{~ B I I ~ 1 0 2. ~ 2 0 ~ d B} )
$$
Answer: I
The period of the sequence obtained by adding two $\mathrm{m}$ sequences with different characteristic polynomials but the same period of $p$ modulo 2 is _.

Options:
A. $p+1$
B. $P$
C. $p^2$
D. $2p$
E. $p+q$
F. $pq$
G. $p^p$
H. $p-1$
I. $3p$
J. $p^3$
Answer: B
Consider a color image consisting of $3 \times 10^{6}$ pixels, each having 16 levels of brightness, with the assumption that each brightness level appears with equal probability. This color image is to be transmitted over a channel with a signal-to-noise ratio of 20 dB, requiring completion in 4 minutes. Calculate the necessary channel bandwidth.

Options:
A. $$
B=\frac{C} {\operatorname{l o g}_{2} ( 1+\frac{S} {N} )}=\frac{4, 2 9 \times1 0^{1}} {\operatorname{l o g}_{2} ( 1+1 1 0 )} \approx6, 7 1 \times1 0^{3} \mathrm{H z}_{*}
$$
B. $$
B=\frac{C} {\operatorname{l o g}_{2} ( 1+\frac{S} {N} )}=\frac{4, 3 2 \times1 0^{1}} {\operatorname{l o g}_{2} ( 1+8 0 )} \approx7, 1 3 \times1 0^{3} \mathrm{H z}_{*}
$$
C. $$
B=\frac{C} {\operatorname{l o g}_{2} ( 1+\frac{S} {N} )}=\frac{3, 9 9 \times1 0^{1}} {\operatorname{l o g}_{2} ( 1+9 3 )} \approx5, 9 4 \times1 0^{3} \mathrm{H z}_{*}
$$
D. $$
B=\frac{C} {\operatorname{l o g}_{2} ( 1+\frac{S} {N} )}=\frac{4, 2 5 \times1 0^{1}} {\operatorname{l o g}_{2} ( 1+1 2 0 )} \approx7, 0 8 \times1 0^{3} \mathrm{H z}_{*}
$$
E. $$
B=\frac{C} {\operatorname{l o g}_{2} ( 1+\frac{S} {N} )}=\frac{3, 9 4 \times1 0^{1}} {\operatorname{l o g}_{2} ( 1+9 0 )} \approx6, 0 3 \times1 0^{3} \mathrm{H z}_{*}
$$
F. $$
B=\frac{C} {\operatorname{l o g}_{2} ( 1+\frac{S} {N} )}=\frac{4, 0 5 \times1 0^{1}} {\operatorname{l o g}_{2} ( 1+1 0 5 )} \approx6, 9 0 \times1 0^{3} \mathrm{H z}_{*}
$$
G. $$
B=\frac{C} {\operatorname{l o g}_{2} ( 1+\frac{S} {N} )}=\frac{4, 1 7 \times1 0^{1}} {\operatorname{l o g}_{2} ( 1+1 0 0 )} \approx6, 2 7 \times1 0^{3} \mathrm{H z}_{*}
$$
H. $$
B=\frac{C} {\operatorname{l o g}_{2} ( 1+\frac{S} {N} )}=\frac{3, 8 7 \times1 0^{1}} {\operatorname{l o g}_{2} ( 1+9 5 )} \approx5, 8 9 \times1 0^{3} \mathrm{H z}_{*}
$$
I. $$
B=\frac{C} {\operatorname{l o g}_{2} ( 1+\frac{S} {N} )}=\frac{4, 1 8 \times1 0^{1}} {\operatorname{l o g}_{2} ( 1+6 5 )} \approx5, 7 5 \times1 0^{3} \mathrm{H z}_{*}
$$
J. $$
B=\frac{C} {\operatorname{l o g}_{2} ( 1+\frac{S} {N} )}=\frac{4, 5 0 \times1 0^{1}} {\operatorname{l o g}_{2} ( 1+7 0 )} \approx6, 4 9 \times1 0^{3} \mathrm{H z}_{*}
$$
Answer: G
In unipolar sinusoidal wave PWM modulation, assuming the number of pulses per half cycle is $7$ and the pulse amplitude is 1.2 times the corresponding sinusoidal wave amplitude, calculate the pulse width according to the principle of area equivalence.

Options:
A. $$
\delta_{1}=0. 0 1 0 T,
\delta_{2}=0. 0 36T,
\delta_{3}=0. 052 T,
\delta_{4}=0. 061 T
$$
B. $$
\delta_{1}=0. 0 1 8 T,
\delta_{2}=0. 0 33T,
\delta_{3}=0. 047 T,
\delta_{4}=0. 065 T
$$
C. $$
\delta_{1}=0. 0 1 1 T,
\delta_{2}=0. 0 34T,
\delta_{3}=0. 056 T,
\delta_{4}=0. 057 T
$$
D. $$
\delta_{1}=0. 0 1 3 T,
\delta_{2}=0. 0 37T,
\delta_{3}=0. 053 T,
\delta_{4}=0. 059 T
$$
E. $$
\delta_{1}=0. 0 1 5 T,
\delta_{2}=0. 0 39T,
\delta_{3}=0. 054 T,
\delta_{4}=0. 060 T
$$
F. $$
\delta_{1}=0. 0 1 4 T,
\delta_{2}=0. 0 38T,
\delta_{3}=0. 055 T,
\delta_{4}=0. 062 T
$$
G. $$
\delta_{1}=0. 0 1 3 T,
\delta_{2}=0. 0 42T,
\delta_{3}=0. 049 T,
\delta_{4}=0. 064 T
$$
H. $$
\delta_{1}=0. 0 1 2 T,
\delta_{2}=0. 0 35T,
\delta_{3}=0. 051 T,
\delta_{4}=0. 058 T
$$
I. $$
\delta_{1}=0. 0 1 7 T,
\delta_{2}=0. 0 41T,
\delta_{3}=0. 048 T,
\delta_{4}=0. 063 T
$$
J. $$
\delta_{1}=0. 0 2 0 T,
\delta_{2}=0. 0 40T,
\delta_{3}=0. 050 T,
\delta_{4}=0. 055 T
$$
Answer: D
In a single-phase AC voltage regulation circuit with resistive load, the output power reaches its maximum value when $\alpha=0^{\circ}$. Find the phase shift triggering angle $a$ when the output power is half of the maximum power,

Options:
A. $$
a=60^{\circ}
$$
B. $$
a=45^{\circ}
$$
C. $$
a=180^{\circ}
$$
D. $$
a=75^{\circ}
$$
E. $$
a=30^{\circ}
$$
F. $$
a=150^{\circ}
$$
G. $$
a=120^{\circ}
$$
H. $$
a=15^{\circ}
$$
I. $$
a=9 0^{\circ}
$$
J. $$
a=10^{\circ}
$$
Answer: I
A step-down chopper circuit has filter component parameters of $L=2 mH, C=330 \mu F$. It is desired that $U_{O}=12 V$ with a chopping frequency of 25kHz. If $U_{s}=25 V$ and the average output current $I_{O}=0.3 A$, calculate the output voltage ripple $\Delta U_{O}$.

Options:
A. $$
1. 8 9 ( \mathrm{m V} )
$$
B. $$
2. 3 0 ( \mathrm{m V} )
$$
C. $$
1. 5 6 ( \mathrm{m V} )
$$
D. $$
1. 9 5 ( \mathrm{m V} )
$$
E. $$
1. 6 4 ( \mathrm{m V} )
$$
F. $$
2. 0 0 ( \mathrm{m V} )
$$
G. $$
2. 5 1 ( \mathrm{m V} )
$$
H. $$
2. 1 5 ( \mathrm{m V} )
$$
I. $$
1. 4 2 ( \mathrm{m V} )
$$
J. $$
1. 2 0 ( \mathrm{m V} )
$$
Answer: A
Three-phase half-wave controlled rectifier circuit with a motor load and a sufficiently large reactor in series. The effective value of the phase voltage $U_{2}=220 V$, the motor load current is 40A, and the total resistance of the load circuit $R_{L}=0.2 \Omega$. Find the average and effective current through the thyristor and the counter-electromotive force of the motor when $\alpha=60^{\circ}$.

Options:
A. $$13.6A,25A,117.8V$$
B. $$12.5A,26A,118.9V$$
C. $$16.2A,21A,125.5V$$
D. $$15.0A,21A,121.4V$$
E. $$12.8A,24A,115.3V$$
F. $$15.7A,22A,110.1V$$
G. $$13.3A,23A,120.7V$$
H. $$14.5A,22A,130.2V$$
I. $$11.9A,23A,134.0V$$
J. $$14.1A,20A,112.6V$$
Answer: G
There is a Cuk converter circuit with a switching frequency of 50kHz. Assuming the output capacitor is large enough to keep the output voltage constant and the power loss of the components is negligible, if the input voltage $U_d = 10V$ and the output voltage $\mathbf{U}_{O}$ is regulated to remain at 5V. Calculate the on-time and off-time of the switch.

Options:
A. $$
6. 6 7 \mu s
$$
$$
1 3. 3 4 \mu s
$$
B. $$
6. 4 3 \mu s
$$
$$
1 3. 5 6 \mu s
$$
C. $$
7. 7 2 \mu s
$$
$$
1 2. 7 8 \mu s
$$
D. $$
6. 6 0 \mu s
$$
$$
1 3. 3 8 \mu s
$$
E. $$
7. 0 1 \mu s
$$
$$
1 2. 9 9 \mu s
$$
F. $$
7. 8 7 \mu s
$$
$$
1 2. 2 3 \mu s
$$
G. $$
5. 5 5 \mu s
$$
$$
1 4. 4 4 \mu s
$$
H. $$
5. 3 4 \mu s
$$
$$
1 4. 6 6 \mu s
$$
I. $$
6. 2 9 \mu s
$$
$$
1 3. 7 9 \mu s
$$
J. $$
5. 9 0 \mu s
$$
$$
1 4. 1 0 \mu s
$$
Answer: A
At the exit of a parking garage, there is only one gate where fees are collected and change is given to drivers. Assuming vehicle arrivals follow a Poisson distribution with a rate of 120 vehicles per hour, and the average duration of fee collection is 15 seconds, following an exponential distribution, calculate the average time consumption in the system and the average waiting time in the system is().

Options:
A. 3.00(min)
B. 0.75(min)
C. 0.30(min)
D. 0.50(min)
E. 1.50(min)
F. 2.00(min)
G. 0.05(min)
H. 0.25(min)
I. 1.00(min)
J. 0.10(min)
Answer: H
After a virus invades the body, the earliest produced immune substance is ().

Options:
A. TNF
B. IL-6
C. IL-1
D. IFN
E. IL-12
F. IL-4
G. IL-2
H. IL-10
I. GM-CSF
J. IL-8
Answer: D
A papillary muscle in the LV ruptures, (Assume that there are no functioning controls, and that the system has reached a new steady state.) The new arterial BP (systolic, diastolic, and mean) drops to 60%' of its original value.
New BP.
120x0.6 =72
80x0.6 = 48
110x0.6 = 66
Crudely approximate the stroke volume delivered to the aorta by making use of the Windkessel approximation is().

Options:
A. $$
\begin{array} {c} {{S V^{\prime}=0. 6 \times8 0 \, c c=\boxed{4 8 \, c c}}} \\ {{\uparrow}} \\ {{o r i g i n a l \, S V}} \\ \end{array}
$$
B. $$
\begin{array} {c} {{S V^{\prime}=0. 9 \times1 0 0 \, c c=\boxed{9 0 \, c c}}} \\ {{\uparrow}} \\ {{o r i g i n a l \, S V}} \\ \end{array}
$$
C. $$
\begin{array} {c} {{S V^{\prime}=0. 8 \times1 1 0 \, c c=\boxed{8 8 \, c c}}} \\ {{\uparrow}} \\ {{o r i g i n a l \, S V}} \\ \end{array}
$$
D. $$
\begin{array} {c} {{S V^{\prime}=0. 1 \times2 0 0 \, c c=\boxed{2 0 \, c c}}} \\ {{\uparrow}} \\ {{o r i g i n a l \, S V}} \\ \end{array}
$$
E. $$
\begin{array} {c} {{S V^{\prime}=0. 4 \times1 2 0 \, c c=\boxed{4 8 \, c c}}} \\ {{\uparrow}} \\ {{o r i g i n a l \, S V}} \\ \end{array}
$$
F. $$
\begin{array} {c} {{S V^{\prime}=0. 7 \times1 0 0 \, c c=\boxed{7 0 \, c c}}} \\ {{\uparrow}} \\ {{o r i g i n a l \, S V}} \\ \end{array}
$$
G. $$
\begin{array} {c} {{S V^{\prime}=0. 3 \times1 6 0 \, c c=\boxed{4 8 \, c c}}} \\ {{\uparrow}} \\ {{o r i g i n a l \, S V}} \\ \end{array}
$$
H. $$
\begin{array} {c} {{S V^{\prime}=0. 5 \times9 0 \, c c=\boxed{4 5 \, c c}}} \\ {{\uparrow}} \\ {{o r i g i n a l \, S V}} \\ \end{array}
$$
I. $$
\begin{array} {c} {{S V^{\prime}=0. 2 \times1 8 0 \, c c=\boxed{3 6 \, c c}}} \\ {{\uparrow}} \\ {{o r i g i n a l \, S V}} \\ \end{array}
$$
J. $$
\begin{array} {c} {{S V^{\prime}=0. 6 \times1 1 0 \, c c=\boxed{6 6 \, c c}}} \\ {{\uparrow}} \\ {{o r i g i n a l \, S V}} \\ \end{array}
$$
Answer: J
Place $0.10\ \text{mol} \ \text{C}_2\text{H}_2$ gas in a sealed container filled with $1.00\ \text{mol} \ \text{O}_2$ with a volume of $10.0 \ \text{dm}^3$, allowing it to completely combust to produce $\text{CO}_2$ and $\text{H}_2\text{O}$. What is the pressure inside the container when the reaction is complete and the temperature is 150°C?

Options:
A. $$
4. 0 8 \times1 0^{2} \mathrm{~ k P a}
$$
B. $$
5. 2 7 \times1 0^{2} \mathrm{~ k P a}
$$
C. $$
4. 1 2 \times1 0^{2} \mathrm{~ k P a}
$$
D. $$
2. 9 4 \times1 0^{2} \mathrm{~ k P a}
$$
E. $$
3. 1 8 \times1 0^{2} \mathrm{~ k P a}
$$
F. $$
2. 4 5 \times1 0^{2} \mathrm{~ k P a}
$$
G. $$
2. 7 6 \times1 0^{2} \mathrm{~ k P a}
$$
H. $$
3. 9 5 \times1 0^{2} \mathrm{~ k P a}
$$
I. $$
3. 6 9 \times1 0^{2} \mathrm{~ k P a}
$$
J. $$
3. 3 3 \times1 0^{2} \mathrm{~ k P a}
$$
Answer: I
LiBr has an NaCl-type crystal structure, with a density of 3.464 g/cm³. What is the distance between Li⁺ and Br⁻?

Options:
A. $$
3 0 5 {\mathrm{~ p m}}
$$
B. $$
2 6 0 {\mathrm{~ p m}}
$$
C. $$
2 7 5 {\mathrm{~ p m}}
$$
D. $$
3 1 5 {\mathrm{~ p m}}
$$
E. $$
3 2 0 {\mathrm{~ p m}}
$$
F. $$
2 8 0 {\mathrm{~ p m}}
$$
G. $$
3 5 0 {\mathrm{~ p m}}
$$
H. $$
2 5 0 {\mathrm{~ p m}}
$$
I. $$
2 9 5 {\mathrm{~ p m}}
$$
J. $$
3 8 0 {\mathrm{~ p m}}
$$
Answer: C
At a certain temperature, the reaction
$$
\mathrm{H}_{2} ( \mathrm{~ g ~} ) \ +\mathrm{B r}_{2} ( \mathrm{~ g ~} ) \ \rightleftharpoons \mathrm{H B r} ( \mathrm{~ g ~} )
$$
has a $K_{c}=8.10 \times 10^{3}$. Calculate the equilibrium conversion rate of $\mathrm{B r}_{2}$ when the initial concentrations of both $\mathrm{H}_{2} (\mathrm{g})$ and $\mathrm{B r}_{2} (\mathrm{g})$ are each $1.00 \; \mathrm{mol} \cdot \mathrm{dm}^{-3}$, and when the initial concentrations of $\mathrm{H}_{2} (\mathrm{g})$ and $\mathrm{B r} (\mathrm{g})$ are $10.00 \, \mathrm{mol} \cdot \mathrm{dm}^{-3}$ and $1.00 \; \mathrm{mol} \cdot \mathrm{dm}^{-3}$, respectively.

Options:
A. $$
9 1. 2\%,\ 9 7. 5 8\%
$$
B. $$
9 2. 6\%,\ 9 6. 0 0\%
$$
C. $$
9 7. 8\%,\ 9 9. 9 9\%
$$
D. $$
8 9. 4\%,\ 9 0. 0 1\%
$$
E. $$
8 5. 7\%,\ 9 3. 6 4\%
$$
F. $$
6 8. 9\%,\ 8 6. 4 7\%
$$
G. $$
8 8. 8\%,\ 9 2. 0 5\%
$$
H. $$
7 6. 5\%,\ 8 8. 2 0\%
$$
I. $$
7 9. 1\%,\ 8 5. 9 3\%
$$
J. $$
8 0. 3\%,\ 9 1. 7 5\%
$$
Answer: C
Prepare 1 dm³ of an HA-NaAc buffer solution with a pH of 5. To ensure buffering capacity, the combined concentration of HAc and its conjugate base must be 2 mol·dm⁻³. Calculate the required amounts of 17 mol·dm⁻³ glacial acetic acid and 6 mol·dm⁻³ NaOH solution, and how much water to add? Given that the $K_s^{\ominus}$ of HAc is $1.8 \times 10^{-5}$.

Options:
A. $$
0. 1 2 \ \mathrm{d m}^{3},\ 0. 2 0 \ \mathrm{d m}^{3},\ 0. 6 8 \ \mathrm{d m}^{3}
$$
B. $$
0. 1 2 \ \mathrm{d m}^{3},\ 0. 2 2 \ \mathrm{d m}^{3},\ 0. 6 6 \ \mathrm{d m}^{3}
$$
C. $$
0. 1 7 \ \mathrm{d m}^{3},\ 0. 2 2 \ \mathrm{d m}^{3},\ 0. 6 1 \ \mathrm{d m}^{3}
$$
D. $$
0. 1 1 \ \mathrm{d m}^{3},\ 0. 2 3 \ \mathrm{d m}^{3},\ 0. 6 6 \ \mathrm{d m}^{3}
$$
E. $$
0. 1 4 \ \mathrm{d m}^{3},\ 0. 2 4 \ \mathrm{d m}^{3},\ 0. 6 4 \ \mathrm{d m}^{3}
$$
F. $$
0. 1 0 \ \mathrm{d m}^{3},\ 0. 2 5 \ \mathrm{d m}^{3},\ 0. 6 5 \ \mathrm{d m}^{3}
$$
G. $$
0. 1 5 \ \mathrm{d m}^{3},\ 0. 2 0 \ \mathrm{d m}^{3},\ 0. 6 5 \ \mathrm{d m}^{3}
$$
H. $$
0. 1 3 \ \mathrm{d m}^{3},\ 0. 2 1 \ \mathrm{d m}^{3},\ 0. 6 6 \ \mathrm{d m}^{3}
$$
I. $$
0. 1 8 \ \mathrm{d m}^{3},\ 0. 2 7 \ \mathrm{d m}^{3},\ 0. 6 0 \ \mathrm{d m}^{3}
$$
J. $$
0. 1 6 \ \mathrm{d m}^{3},\ 0. 2 6 \ \mathrm{d m}^{3},\ 0. 6 2 \ \mathrm{d m}^{3}
$$
Answer: B
Given that $K_{\mathrm{sp}}^{\ominus} (\mathrm{HgI}_{2}) = 2.9 \times 10^{-29}$, $K_{\mathrm{Steady state}}^{\ominus} \mid\left[ \mathrm{HgI}_{4} \right]^{2-} \mid = 6.8 \times 10^{29}$; $K_{\mathrm{sp}}^{\ominus} (\mathrm{CdS}) = 8.0 \times 10^{-27}$, $K_{Steady state}^{\ominus} \mid [\mathrm{CdI}_{4}]^{2-} \mid = 2.6 \times 10^{5}$. Assume the reaction of $\mathrm{HgI}_{2}$ with $\mathrm{KI}$ solution proceeds according to the following equation:
$$
\mathrm{HgI}_{2} + 2 \mathrm{I}^{-} = \left[ \mathrm{HgI}_{4} \right]^{2-}$$
And the reaction of $\mathrm{CdS}$ with $\mathrm{KI}$ solution proceeds according to the following equation:
$$
\mathrm{CdS} + 4 \mathrm{I}^{-} = \left[ \mathrm{CdI}_{4} \right]^{2-} + \mathrm{S}^{2-}$$
What is the equilibrium constant for the reaction of $\mathrm{HgI}_{2}$ with $\mathrm{KI}$ solution?

Options:
A. $25.3$
B. $8.1$
C. $11.8$
D. $30.4$
E. $5.7$
F. $3.2$
G. $14.5$
H. $19.7$
I. $7.9$
J. $12.6$
Answer: H
Given that the $K_{\mathrm{sp}}^{\ominus}$ for CuS is $6.3 \times 10^{-36}$ and the $K_{a}^{\ominus}$ for $\mathrm{H}_{2} \mathrm{S}$ is $1.4 \times 10^{-20}$, in a $1.0 \ \mathrm{mol} \cdot \mathrm{dm}^{-3} \, \mathrm{CuCl}_{2}$ solution containing $10.0 \ \mathrm{mol} \cdot \mathrm{dm}^{-3} \ \mathrm{HCl}$, $\mathrm{H_{2} S}$ gas is bubbled in until saturation. Determine the concentrations $c \left( \mathrm{H}^{+} \right)$ and $c \left( \mathrm{Cu}^{2+} \right)$ in the solution when equilibrium is reached.

Options:
A. $$
6. 1 \times1 0^{-1 2} \mathrm{~ m o l ~ \cdot~ d m}^{-3}
$$
B. $$
1. 1 \times1 0^{-1 8} \mathrm{~ m o l ~ \cdot~ d m}^{-3}
$$
C. $$
2. 3 \times1 0^{-1 4} \mathrm{~ m o l ~ \cdot~ d m}^{-3}
$$
D. $$
8. 9 \times1 0^{-1 7} \mathrm{~ m o l ~ \cdot~ d m}^{-3}
$$
E. $$
4. 8 \times1 0^{-1 5} \mathrm{~ m o l ~ \cdot~ d m}^{-3}
$$
F. $$
6. 5 \times1 0^{-1 3} \mathrm{~ m o l ~ \cdot~ d m}^{-3}
$$
G. $$
9. 7 \times1 0^{-1 1} \mathrm{~ m o l ~ \cdot~ d m}^{-3}
$$
H. $$
3. 2 \times1 0^{-1 2} \mathrm{~ m o l ~ \cdot~ d m}^{-3}
$$
I. $$
5. 4 \times1 0^{-1 6} \mathrm{~ m o l ~ \cdot~ d m}^{-3}
$$
J. $$
7. 6 \times1 0^{-1 9} \mathrm{~ m o l ~ \cdot~ d m}^{-3}
$$
Answer: F
Male, 60 years old. Diagnosed with a right frontal-parietal acute subdural hematoma via CT scan 2 months ago. The current CT shows an enlargement of the affected area, displaying a low-density upper region and a high-density lower region. Diagnose this situation as ().

Options:
A. Chronic Hemorrhage in Ischemic Stroke
B. Acute Hemorrhage in Intracerebral Aneurysm
C. Acute Hemorrhage in Chronic Subdural Hematoma
D. Progressive Encephalopathy in Tumoral Lesion
E. Traumatic Edema in Occipital Subdural Region
F. Acute on Chronic Subarachnoid Hemorrhage
G. Subacute Hemorrhage in Epidural Hematoma
H. Acute Infarction in Frontotemporal Lobe
I. Hemorrhagic Transformation in Ischemic Stroke
J. Reactive Edema in Subdural Hematoma
Answer: C
The MRI signal of a submucosal sinus cyst is ().

Options:
A. Medium T.WI, Medium T, WI signal
B. Long T.WI, Long T, WI signal
C. Short T.WI, Short T, WI signal
D. Long T.WI, Long T, HI signal
E. Short T.WI, Long T, WI signal
F. Long T.WI, Long T, TI signal
G. Long T.WI, Short T, WI signal
H. Medium T.WI, Long T, WI signal
I. Long T.WI, Medium T, WI signal
J. Long T.WI, Short T, TI signal
Answer: B
Male, 16 years old. Underwent a nasopharyngeal CT scan due to recurrent nosebleeds, which revealed a large soft tissue mass on the posterior wall of the nasopharynx apex, extending forward into the nose, ethmoid sinus, and maxillary sinus. It extends laterally through the enlarged superior orbital fissure into the pterygopalatine fossa and infratemporal fossa, and upward through the sphenoid sinus and foramen lacerum reaching the cavernous sinus, with compressive changes observable in the adjacent bone. Post-enhancement scan shows significant tumor enhancement, and it should primarily be considered as a diagnosis of ().

Options:
A. Inverted papilloma
B. Fibrous dysplasia infection
C. Sinonasal papilloma
D. Silent sinus syndrome
E. Meningioma invasion
F. Metastatic carcinoma
G. Nasopharyngeal angiofibroma
H. Juvenile sinus sarcoma
I. Chronic sinusitis result
J. Nasopharyngeal carcinoma
Answer: G
The diagnostic value of bronchiectasis on X-ray film, which of the following is most significant?

Options:
A. Increased lung vascularity
B. Cystic or honeycomb shadow
C. Pleural thickening liner style
D. Nodular formations expansion
E. Ground-glass opacification
F. Pronounced airway scarring
G. Peripheral lung fistulae
H. Diaphragmatic dome elevation
I. Linear streaking patterns
J. Mucoid impaction emergence
Answer: B
Pulmonary congestion appears on plain films as: _____. ① Enlarged pulmonary hila, with clear vascular margins; ② Enlarged pulmonary hila, with unclear structure and blurred vascular margins; ③ General dilation of pulmonary vessels, blurred margins, striped appearance; ④ Proportionally thickened pulmonary vessels with sharp edges; ⑤ Thickening of upper pulmonary veins, thinning of lower pulmonary veins.

Options:
A. ①③④
B. ②③④
C. ②③⑤
D. ①②③
E. ①②④
F. ①③⑤
G. ②④⑤
H. ①④⑤
I. ③④⑤
J. ①②⑤
Answer: C
When using the SE sequence to observe the left atrium in the case of mitral stenosis, it appears as ().

Options:
A. Turbulent flow with high signal
B. Slow blood flow with high signal
C. Gradual flow with reduced intensity
D. Uniform flow showing low intensity
E. Rapid contraction with low signal
F. Swift blood flow with low signal
G. Pooling blood with subtle signal
H. Steady flow with low signal intensity
I. Slow chamber expansion high signal
J. Fast-moving blood with weak signal
Answer: B
Male, 50 years old. Ultrasound shows a 1.5 cm hypoechoic mass with capsule in the right lobe of liver. MRI scan shows slightly low signal intensity on $\mathbf{T}_{1}$-weighted images and isointense signal on $\mathbf{T}_{2}$-weighted images. Besides small hepatocellular carcinoma, which of the following conditions should be considered?

Options:
A. Solitary Cystic Lesion of Hepatic
B. Metastatic Neuroendocrine Tumor Liver
C. Inflammatory Pseudotumor of the Liver
D. Fatty Liver Hepatomegaly Indication Present
E. Regenerative Nodules in Cirrhosis Case
F. Hepatic Hemangioma of the Liver
G. Liver Adenomatosis Condition
H. Malignant Fibrous Histiocytoma Found
I. Cholangiocellular Carcinoma Present
J. Focal Nodular Hyperplasia of Liver
Answer: C
MRI findings of cirrhotic nodules should be ().

Options:
A. same T1, short T2
B. different
C. short T1, long T2
D. long T1, same T2
E. long T1, same T1
F. short T1, short T2
G. short T1, same T2
H. same T1, same T2
Answer: F
A uniform plane wave propagates in the air along the z-direction, with its electric field intensity $E$ given by
$E = a_{z} E_{z} = a_{z} 5 \times 10^{-4} \cos \left( 2 \times 10^{7} \pi t - k_{0} z + \frac{\pi}{4} \right) \quad \mathrm{V/m}.$
Calculate the value of $k_{0}$ and the position where $E_{z} = 0$ when $t = 3$ ms.

Options:
A. $$
z=2 \times1 0^{5}+\frac{1 9} {4}-\frac{1 1} {2} ( 2 n+1 ) \quad\mathrm{m}
$$
B. $$
z=6 \times1 0^{5}+\frac{1 6} {4}-\frac{1 4} {2} ( 2 n+1 ) \quad\mathrm{m}
$$
C. $$
z=7 \times1 0^{5}+\frac{1 8} {4}-\frac{1 2} {2} ( 2 n+1 ) \quad\mathrm{m}
$$
D. $$
z=3 \times1 0^{5}+\frac{1 2} {4}-\frac{1 8} {2} ( 2 n+1 ) \quad\mathrm{m}
$$
E. $$
z=4 \times1 0^{5}+\frac{1 7} {4}-\frac{1 3} {2} ( 2 n+1 ) \quad\mathrm{m}
$$
F. $$
z=8 \times1 0^{5}+\frac{1 3} {4}-\frac{1 7} {2} ( 2 n+1 ) \quad\mathrm{m}
$$
G. $$
z=9 \times1 0^{5}+\frac{1 5} {4}-\frac{1 5} {2} ( 2 n+1 ) \quad\mathrm{m}
$$
H. $$
z=1 \times1 0^{5}+\frac{1 1} {4}-\frac{1 9} {2} ( 2 n+1 ) \quad\mathrm{m}
$$
I. $$
z=5 \times1 0^{5}+\frac{1 4} {4}-\frac{1 6} {2} ( 2 n+1 ) \quad\mathrm{m}
$$
J. $$
z=0 \times1 0^{5}+\frac{1 0} {4}-\frac{1 0} {2} ( 2 n+1 ) \quad\mathrm{m}
$$
Answer: G
A waveguide with dimensions $a \times b = 72.14 \, \mathrm{mm} \times 34.04 \, \mathrm{mm}$ is transmitting a wavelength of 10 cm in the $\mathbf{TE}_{10}$ mode. If the waveguide material is brass and the waveguide length is 100 m, calculate its conductor attenuation.

Options:
A. $$
3. 9 4 ~ \mathrm{d B}
$$
B. $$
4. 5 5 ~ \mathrm{d B}
$$
C. $$
3. 7 3 ~ \mathrm{d B}
$$
D. $$
7. 5 1 ~ \mathrm{d B}
$$
E. $$
6. 3 2 ~ \mathrm{d B}
$$
F. $$
2. 3 7 ~ \mathrm{d B}
$$
G. $$
5. 1 8 ~ \mathrm{d B}
$$
H. $$
4. 0 6 ~ \mathrm{d B}
$$
I. $$
2. 6 9 ~ \mathrm{d B}
$$
J. $$
1. 8 4 ~ \mathrm{d B}
$$
Answer: C
A coaxial line with inner and outer radii of $a$ and $b$, respectively, is filled with an ideal dielectric with a relative permittivity of 2.25 between the inner and outer conductors. Given $a = 5 \mathrm{~ mm}$, determine the range of operating frequencies for which this coaxial line transmits only the TEM mode under conditions of minimum conductor attenuation.

Options:
A. $$
0 < f < f_{m a x}=2. 7 5 \mathrm{~ G H z}
$$
B. $$
0 < f < f_{m a x}=3. 4 0 \mathrm{~ G H z}
$$
C. $$
0 < f < f_{m a x}=2. 8 7 \mathrm{~ G H z}
$$
D. $$
0 < f < f_{m a x}=3. 0 1 \mathrm{~ G H z}
$$
E. $$
0 < f < f_{m a x}=2. 2 0 \mathrm{~ G H z}
$$
F. $$
0 < f < f_{m a x}=2. 5 3 \mathrm{~ G H z}
$$
G. $$
0 < f < f_{m a x}=3. 1 5 \mathrm{~ G H z}
$$
H. $$
0 < f < f_{m a x}=1. 9 5 \mathrm{~ G H z}
$$
I. $$
0 < f < f_{m a x}=2. 6 9 \mathrm{~ G H z}
$$
J. $$
0 < f < f_{m a x}=1. 8 7 \mathrm{~ G H z}
$$
Answer: I
Example 6.8: Given that the amplitude of the electric field intensity at a distance of 10 km in the direction of maximum radiation of a half-wave dipole in free space is 0.01 V/m, with the operating frequency of the radiated electromagnetic wave being 300 MHz. What is the length of one arm of the half-wave dipole and its radiated power?

Options:
A. $$
h=0. 2 0 \ \mathrm{m}
$$
$$Im=2.000A$$
B. $$
h=0. 3 5 \ \mathrm{m}
$$
$$Im=1.600A$$
C. $$
h=0. 2 5 \ \mathrm{m}
$$
$$Im=1.667A$$
D. $$
h=0. 2 2 \ \mathrm{m}
$$
$$Im=2.500A$$
E. $$
h=0. 1 8 \ \mathrm{m}
$$
$$Im=1.900A$$
F. $$
h=0. 4 0 \ \mathrm{m}
$$
$$Im=1.200A$$
G. $$
h=0. 2 8 \ \mathrm{m}
$$
$$Im=1.400A$$
H. $$
h=0. 3 0 \ \mathrm{m}
$$
$$Im=1.500A$$
I. $$
h=0. 1 5 \ \mathrm{m}
$$
$$Im=1.800A$$
J. $$
h=0. 3 2 \ \mathrm{m}
$$
$$Im=1.000A$$
Answer: C
Given a microstrip substrate with a relative dielectric constant $\varepsilon_{\mathrm{r}}=3.78$, thickness $h=0.635 \ \text{mm}$, characteristic impedance $Z_{\mathrm{c}}=50 \ \Omega$, and operating frequency $f=10 \ \text{GHz}$. Determine the guided wavelength of the microstrip line.

Options:
A. 3.245,1.80cm
B. 3.012,1.59cm
C. 2.842,1.79cm
D. 3.567,1.68cm
E. 2.931,1.73cm
F. 3.723,1.55cm
G. 2.990,1.85cm
H. 3.056,1.89cm
I. 2.785,1.63cm
J. 2.867,1.92cm
Answer: E