Mechanics

1.	Which is the correct formula to find acceleration?
	A. a = v-u/t
	B. a=μ+vt
	C. a=v+u/t
	D. a=v+u/2 Option”A” is correct. Acceleration (a) is the change in velocity (Δv) over the change in time (Δt), represented by the equation a = Δv/Δt.

2.	Which physical quantity is obtained from the ratio of momentum and velocity of a substance?
	A. Speed
	B. Acceleration
	C. Mass
	D. Force Option”C” is correct. Mass is obtained as the ratio of momentum and velocity of matter and its S.I unit is Kg. Momentum of a moving body is the quantity of its motion, measured as a product of its mass and velocity.

3.	What is the dimension of Plank’s constant?
	A. Energy
	B. Linear speed
	C. Angular Momentum
	D. Force Option”C” is correct. the dimension of Planck’s constant is the same as the dimension of angular momentum. Note: The quantity h is called the Planck’s constant. It is a with its value h=6.626×1034 Joule second.

4.	A girl is swinging in a sitting position on a swing, the time period of oscillations when the stick is standing
	A. Will decrease
	B. Will be more
	C. Depends on the height of the girl
	D. Will be refracted Option”A” is correct. When a girl stands up on a swing, the position of the center of mass of the girl is raised. Due to this the effective length of the pendulum decreases, hence the time period of the swing decreases.

5.	Suddenly a boy comes and sits in a rotating circle, will the angular velocity of the table be affected?
	A. Will decrease
	B. Will increase
	C. Will remain the same
	D. Nothing can be said Option”A” is correct. When the boy sits on the rotating table, then he starts rotating too with the table. Therefore, angular velocity is not constant and changes with time. Hence, angular momentum will remain conserved for the table-boy system

6.	If the velocity of a moving object is doubled, its –
	A. Acceleration is doubled
	B. Kinetic energy doubles
	C. Kinetic energy quadruples
	D. Load doubles Option”C” is correct. Kinetic energy depends on the velocity of the object squared. This means that when the velocity of an object doubles, its kinetic energy quadruples.

7.	There is a difference between mass and weight of a body because
	A. Mass is variable, while weight is constant
	B. Mass remains constant while weight is variable
	C. Both are true
	D. Both are wrong Option”B” is correct. The difference between mass and weight is that mass is the amount of matter in a material, while weight is a measure of how the force of gravity acts upon that mass. Mass is the measure of the amount of matter in a body.

8.	There is no change in the position and direction of any stationary or moving object unless an external force acts on it.
	A. Newton’s first law of motion
	B. Newton’s second law of motion
	C. Newton’s third law of motion
	D. Galileo’s laws of motion Option”A” is correct

9.	Acceleration produced in a body by an unbalanced force
	A. Is inversely proportional to the force
	B. Is directly proportional to the force
	C. Is independent of force
	D. Becomes zero Option”B” is correct. When a force is applied to a body its velocity changes. It has been found that acceleration produced in a body is directly proportional to the unbalanced force applied to the body and inversely proportional to the mass of the body.

10.	According to Newton’s third law of motion, action and reaction pair :
	A. always act on the same body
	B. always act on different bodies in opposite directions
	C. have same magnitude and directions
	D. act on either body at normal to each other Option”C” is correct. For every action, there is an equal and opposite reaction. The statement means that in every interaction, there is a pair of forces acting on the two interacting objects. The size of the forces on the first object equals the size of the force on the second object. The direction of the force on the first object is opposite to the direction of the force on the second object. Forces always come in pairs – equal and opposite action-reaction force pairs

Pages: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22