MCQ Collection
Pakistan MCQs
Practice Pakistan questions with answers and explanations.
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Correct Answer: C. Conservation of energy in thermal processes
Explanation:
The change in internal energy equals heat added minus work done by the system.
It is an energy-balance statement.
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Correct Answer: C. 30,000 J
Explanation:
Convert 5 minutes to 300 seconds and use E=Pt.
E=100×300 = 30,000 J.
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Correct Answer: D. No heat engine can convert all absorbed heat into work
Explanation:
Real processes have a preferred direction and generate entropy.
Some heat must be rejected by a cyclic heat engine.
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Correct Answer: D. Oscillation in which acceleration is proportional to displacement and directed toward equilibrium
Explanation:
In SHM, the restoring influence grows with displacement.
The acceleration always points toward the equilibrium position.
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Correct Answer: A. 300 K
Explanation:
Kelvin temperature is Celsius temperature plus about 273.
27+273 = 300 K.
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Correct Answer: A. Maximum displacement from equilibrium
Explanation:
Amplitude measures the largest excursion from equilibrium.
It affects energy but not the ideal SHM period.
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Correct Answer: B. 37°C
Explanation:
Celsius temperature is kelvin temperature minus about 273.
310-273 = 37°C.
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Correct Answer: B. Time taken for one complete cycle
Explanation:
The period is measured in seconds.
It is the reciprocal of frequency.
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Correct Answer: C. 42,000 J
Explanation:
Use Q=mcΔT.
Q=2×4200×5 = 42,000 J.
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Correct Answer: C. Number of complete cycles per second
Explanation:
Frequency is measured in hertz.
One hertz means one cycle per second.
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Correct Answer: D. 30°C
Explanation:
Use ΔT=Q/(mc).
6000/(0.5×400)=30°C.
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Correct Answer: D. Large-amplitude response when driving frequency matches a natural frequency
Explanation:
At resonance, energy transfer from the driver is especially effective.
Damping limits the amplitude.
