Physics - Study Mode
[#1151] An object at rest will remain at rest and an object in motion will remain in motion until and unless it is acted upon by an external force. This is Newton's
Correct Answer
(A) First law
Explanation
Solution: An object at rest will remain at rest and an object in motion will remain in motion until and unless it is acted upon by an external force. This is Newton's first law of motion.
[#1152] What is the force of attraction between any two bodies by virtue of their masses is called?
Correct Answer
(B) Gravitational Force
Explanation
Solution: The attractive force that the celestial bodies exert on other masses by virtue of their total mass is called the force of gravity or gravitational force.
[#1153] If a boy sitting in a train, which is moving at a constant velocity, throws a ball straight up into the air, the ball will
Correct Answer
(C) Fall into his hand
Explanation
Solution: The ball is thrown in vertically upward direction and given that the train is moving up with a constant velocity. Therefore, the horizontal velocity of the train and ball are both same. And, the ball travels the same horizontal distance as that of the train. Therefore, the ball will come back into the hands of thrower.
[#1154] When a bar magnet is cut into two equal halves, the pole strength of each piece –
Correct Answer
(D) Remains the same
Explanation
Solution: The pole strength of each piece when a bar magnet is cut into two equal halves perpendicular to its length is the same as the pole strength of the original bar magnet. However, the magnetic moment of each piece is half the magnetic moment of the original bar magnet.
[#1155] A permanent magnet can affect
Correct Answer
(C) Both A & B
Explanation
Solution: A permanent magnet can affect both magnets and electromagnets.