Physics Questions Practice Question and Answer
8 Q: The coefficient performance of a refrigerator is 5. If the temperature inside the freezer is -20℃, calculate the heat rejected to the surrounding
1095 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: Can eyes with vision be seen clearly?
1095 05fe423abeee69a704db5d457
5fe423abeee69a704db5d457- 1Nearby objectsfalse
- 2Big itemsfalse
- 3distant objectstrue
- 4None of thesefalse
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Answer : 3. "distant objects"
Q: The measure of inductance is
1095 161655ebe3d260361529b137f
61655ebe3d260361529b137f- 1Henrytrue
- 2Ohmfalse
- 3Amperefalse
- 4Coulombfalse
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Answer : 1. "Henry "
Q: Weighing 1 kilogram is the weight.
1093 061655de87d6182610f5d76ff
61655de87d6182610f5d76ff- 11 Nfalse
- 210 Nfalse
- 39.8 Ntrue
- 49 Nfalse
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Answer : 3. "9.8 N "
Q: Who gave the theory of gravity?
1091 061655b5c3d260361529b0876
61655b5c3d260361529b0876- 1Isaac Newtontrue
- 2John Adamsfalse
- 3Charles Newtonfalse
- 4Charles Babbagefalse
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Answer : 1. "Isaac Newton "
Q: An object starts moving in its steady state. It attains a speed of 5 m / s in 2 seconds. What will be its acceleration?
1082 05f869de3e5230d620733716e
5f869de3e5230d620733716e- 12.5 m/sec2true
- 22 m/sec2false
- 31 m/sec2false
- 40.4 m/sec2false
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Answer : 1. "2.5 m/sec2"
Q: Which of the person with long vision defect has glasses?
1080 05fe41d33438750744e325bce
5fe41d33438750744e325bce- 1concave lensfalse
- 2Bifocal lensfalse
- 3convex lenstrue
- 4cylindrical lensfalse
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Answer : 3. "convex lens"
Q: A potentiometer is considered a versatile and accurate device to make an electrical measurement of EMF. Why?
1063 063c8d7f2bdbddb32fda0219d
63c8d7f2bdbddb32fda0219d- 1Because the method involves a combinationfalse
- 2There are cells involvedfalse
- 3Because of potential gradientsfalse
- 4As there is no flow of current through the galvanometertrue
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Answer : 4. "As there is no flow of current through the galvanometer"
Explanation :
A potentiometer is an accurate and versatile device to make electrical measurements of emf because the method involves a condition of no current flow through the galvanometer, the device can be used to measure potential difference, internal resistance of a cell and compare emf's of two sources. Q.