Gravitation Test - 12

A spring balance is used to determine the force exerted on an object by Earth. The magnitude of force exerted by Earth on the object is equal to its weight. Hence, a spring balance can be used to measure weight.

The correct answer is C.

Why alternative A is wrong:

A ruler is used to measure the length of an object.

Why alternative B is wrong:

A watch is used to measure time.

Why alternative D is wrong:

A measuring cylinder is used to measure the volume of a liquid.

The gravitational force exerted on a freely falling ball is constant; hence, the ball will fall with constant acceleration.

The correct answer is C.

Why alternatives A and B are wrong:

A freely falling ball has a constant acceleration. As a result, speed will increase gradually.

Why alternative D is wrong:

Since the force on the ball remains constant, the acceleration will also be constant.

Gravity is the phenomenon through which all the heavy objects tend to fall on earth. A magnet falls on the ground because of the gravitational force on earth.

The correct answer is D.

Why alternative A is wrong:

Although there is a little magnetic force between magnet and the earth, this force is not responsible for the fall of the magnet on the ground.

Why alternative B is wrong:

When two surfaces move in contact with each other, frictional force arises between them. This force is not responsible for the falling of a body on earth.

Why alternative C is wrong:

The electrostatic force is not responsible for the magnet to fall on the ground.

Mass is the measure of the amount of material present in an object, while weight is the measure of gravitational force acting on it. Hence, mass and weight of an object are correctly defined in table A

The correct answer is A.