Physics Practice Question and Answer
8 Q: What type of current is obtained from dynamo?
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5fe45b9a00c5087b4d132da3- 1Direct Sectiontrue
- 2alternating currentfalse
- 3both streamsfalse
- 4None of thesefalse
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Answer : 1. "Direct Section"
Q: Who is considered as the ultimate source of all forms of energy?
710 060b4b23cc6545e407514f717
60b4b23cc6545e407514f717- 1Coalfalse
- 2Atomfalse
- 3Waterfalse
- 4Suntrue
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Answer : 4. "Sun"
Q: If the kinetic energy of a satellite is halved, its orbital radius becomes _____
705 063c7b9788731ac33279af158
63c7b9788731ac33279af158- 1½ timestrue
- 22 timesfalse
- 34 timesfalse
- 4Infinityfalse
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Answer : 1. "½ times"
Explanation :
radius of its orbit will become half.
Q: What type of energy is used to perform bodily functions?
704 060b4b0f6517f2874d53f51b2
60b4b0f6517f2874d53f51b2- 1electric energyfalse
- 2Solar energyfalse
- 3muscle energytrue
- 4Chemical energyfalse
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Answer : 3. "muscle energy"
Q: An object weights the maximum in:
701 061655a8fd881f96172321665
61655a8fd881f96172321665- 1Hydrogenfalse
- 2Vacuumtrue
- 3Airfalse
- 4Waterfalse
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Answer : 2. "Vacuum "
Q: The coefficient performance of a refrigerator is 5. If the temperature inside the freezer is -20℃, calculate the heat rejected to the surrounding
701 063c921551e8e3f3e1a3a5a0a
63c921551e8e3f3e1a3a5a0a- 1110Ctrue
- 2false
410C
- 3false
210C
- 4false
310C
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Answer : 1. "110C"
Explanation :
A heat pump is a heat engine working in reverse direction. A refrigerator is basically a heat pump, which is used to pump heat (absorbed from materials at lower temperatures inside the refrigerator) to the surroundings at higher temperatures. The coefficient of performance of a refrigerator is defined as the ratio of heat removed
Why
2
Energy from inside the refrigerator per cycle
w
given per cycle for heat removal,
α
,
Why
2
,
w
,
Q: What does pupil come in bright light?
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5fe423549f9e9d787c92d003- 1bigfalse
- 2smalltrue
- 3No changefalse
- 4None of thesefalse
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Answer : 2. "small"
Q: The sum of the change in kinetic and potential energy is always-
686 0608929c2fd171c780883f502
608929c2fd171c780883f502- 1Zerotrue
- 2Positivefalse
- 3Negativefalse
- 4None of the abovefalse
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