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Practice MCQ Questions and answers on Physics-GK

Learn and practice General Knowledge questions and answers on Physics with very easy and understandable explanations. GK questions are very helpful different type of competitive exams. Page-8 section-8

Each section contains 100 MCQs on Physics .
71
A person does some work of 1,000 J in 2 s. His power will be ________
Discuss
Answer & Solution
Answer: Option C
Solution:
Power = work / time
= 1000 / 2
= 500 W
72
Which results in an increase in power?
Discuss
Answer & Solution
Answer: Option A
Solution:
By doing more work in less time we can increase the power. And, Power is inversely proportional to time taken to do a work. So, when we do more work in lesser time , power will also increase.
73
What device converts light energy to electrical energy?
Discuss
Answer & Solution
Answer: Option B
Solution:
Photovoltaic cell converts light energy to electrical energy.
74
In a water lifting electric pump, we convert
Discuss
Answer & Solution
Answer: Option A
Solution:
In a water lifting electric pump, we convert electrical energy into potential energy.
75
The device which converts sound energy into electrical energy is called
Discuss
Answer & Solution
Answer: Option C
Solution:
The device which converts sound energy into electrical energy is called microphone.
76
What is the SI unit of Power?
Discuss
Answer & Solution
Answer: Option B
Solution:
Watt is the SI unit of power.
77
For which one of the following does the centre of mass lie outside the body?
Discuss
Answer & Solution
Answer: Option C
Solution:
The centre of mass lie outside the body for a ring.
78
When a pail of water is swung in a vertical circle, the water does not fall out at the top of the loop when the speed is
Discuss
Answer & Solution
Answer: Option B
Solution:
When a pail of water is swung in a vertical circle, the water does not fall out at the top of the loop when the speed is great enough. At every point in the circle the water tries to fall vertically out due to the force of gravity g but also tries to move in a straight line due to its circular motion.
79
Fat can be seperated from milk in a cream seperator because of :
Discuss
Answer & Solution
Answer: Option D
Solution:
A separator is a high-speed centrifuge that acts on the principle that cream or butterfat is lighter than other components in milk. Fat can be separated from milk in a cream separator because of Centrifugal forces.
80
In case of uniform circular motion, the acceleration is
Discuss
Answer & Solution
Answer: Option A
Solution:
In case of uniform circular motion, the acceleration is variable in magnitude but constant in direction.