Directions: In each of the following questions, a statement of Assertion is given and a corresponding statement of Reason is given just below it. Of the statements, given below, mark the correct answer as:
(a) Both assertion and reason are true and reason is the correct explanation of assertion.
(b) Both assertion and reason are true but reason is not the correct explanation of assertion.
(c) Assertion is true but reason is false.
(d) Both Assertion and Reason are false.
Q.1. Assertion : Universal gravitational constant G is a scalar quantity.
Reason : The value of G is same through out the universe.
Q.2. Assertion : When distance between two bodies is doubled and also mass of each body is doubled, then
the gravitational force between them remains the same.
Reason : According to Newton’s law of gravitation, product of force is directly proportional to the product
mass of bodies and inversely proportional to square of the distance between them.
Q.3. Assertion : A man is sitting in a boat which floats on a pond. If the man drinks some water from the pond, the level of water in the pond will decrease.
Reason : The weight of the liquid displaced by the body is greater than the weight of the body.
Q.4. Assertion : During a journey from the earth to the moon and back, maximum fuel is spent to overcome the earth’s gravity at take off.
Reason : Earth’s mass is much greater than that of the moon.
Q.5. Assertion : Any two objects in the universe attract each other by a force called gravitation force.
Reason : The force of gravitation exerted by the earth is called gravity.
Q.6. Assertion : An object floats if it displaces an amount of liquid whose weight is greater than the actual
weight of the object.
Reason : During floatation an object experiences no net force in the downward direction.
Q.7. Assertion : Weight of a body on earth is equal to the force with which the body is attracted towards the earth.
Reason : Weight of a body is independent of the mass of the body.
Q.8. Assertion : If we drop a stone and a sheet of paper from a balcony of first floor, then stone will reach the
Reason : The resistance due to air depends on velocity only.
Q.9. Assertion : The density of a liquid depends upon the nature and temperature of the liquid.
Reason : The volume of the liquid depends upon temperature.
Q.10. Assertion : The value of acceleration due to gravity changes with the height, depth and shape of the earth.
Reason : Acceleration due to gravity is zero at the centre of the earth.
Q.11. Assertion : It is the gravitational force exerted by the sun and the moon on the sea water that causes to the formation of tides in the sea.
Reason : Gravitational force of attraction is a strong force.