Physics Questions Answers
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36. What is unit of Astronomical distance ?
- light year
- angstrom
- weber
- lux
Answer And Explanation
Answer: Option A
Explanation:
angstrom is used to measure wave length,
weber is used to measure Magnetic flux,
lux is used to measure Intensity of illumination. -
37. Scalar Quantities are
- physical quantities which have magnitude only and no direction
- physical quantities which have no magnitude only and only direction
- physical quantities which have magnitude only and direction
- physical quantities which have no magnitude and no direction
Answer And Explanation
Answer: Option A
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38. What is displacement ?
- Longest distance covered by a body in a random direction.
- Shortest distance covered by a body in a random direction.
- Shortest distance covered by a body in a definite direction.
- Longest distance covered by a body in a definite direction.
Answer And Explanation
Answer: Option C
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39. Which law is also called law of inertia ?
- Newton first law
- Newton second law
- Newton third law
- All of above
Answer And Explanation
Answer: Option A
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40. What is newton third law of motion ?
- Every body maintains its initial state rest or motion unless no external force is applied.
- The rate of change in momentum of a body is directly proportional to the applied force on the body and takes place in the direction of force.
- To every action there is equal and opposite reaction.
- None of above.
Answer And Explanation
Answer: Option C
Explanation:
Newton First Law of Motion : Every body maintains its initial state rest or motion unless no external force is applied.
Newton Second Law of Motion : The rate of change in momentum of a body is directly proportional to the applied force on the body and takes place in the direction of force. -
41. If no external force acts on a system of bodies, the total linear momentum of the system of bodies remains constant. Which law states this ?
- Newton first law
- Newton second law
- Newton third law
- Principle of conservation of linear momentum
Answer And Explanation
Answer: Option D
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42. The rotational effect of a force on a body about an axis of rotation is described in terms of
- Centre of gravity
- Centripetal force
- Centrifugal force
- Moment of force
Answer And Explanation
Answer: Option D