#### 11th Standard Physics Laws of Motion English Medium Free Online Test One Mark Questions 2020 - 2021

11th Standard

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Physics

Time : 00:20:00 Hrs
Total Marks : 20

20 x 1 = 20
1. When a car takes a sudden left turn in the curved road, passengers are pushed towards the right due to

(a)

inertia of direction

(b)

inertia of motion

(c)

inertia of rest

(d)

absence of inertia

2. Two masses m1 and m2 are experiencing the same force where m1 < m2.The ration of their acceleration $\frac { { a }_{ 1 } }{ { a }_{ 2 } }$is

(a)

1

(b)

less than 1

(c)

greater than 1

(d)

all the three cases

3. Force acting on the particle moving with constant speed is

(a)

always zero

(b)

need not be zero

(c)

always non zero

(d)

cannot be concluded

4. The centrifugal force appears to exist

(a)

only in inertial frames

(b)

only in rotating frames

(c)

in any accelerated frame

(d)

both in inertial and non-inertial frames

5.  Physical independence of force is a consequence of

(a)

III law of motion

(b)

I law

(c)

II law

(d)

All

6. A ball with an initial momentum P collides normally with a rigid wall. If P1 is the linear momentum after the perfectly elastic collision, then

(a)

P1 = P

(b)

P1 = -P

(c)

P1 = 2P

(d)

P1 =-2P

7. A block of mass M is pulled along a horizontal frictionless surface by a rope of mass m. A force F is applied at the free end of the rope. The force exerted by the rope on the block

(a)

$\frac { MF }{ M+m }$

(b)

$\frac { M+m }{ MF }$

(c)

$\frac { M }{ M-m }$ .F

(d)

$\frac { M-m }{ M }$ .F

8. A block is kept on a frictionless inclined surface with angle of inclination ∝, The incline is given an acceleration a to keep the block stationary. Then a is equal to

(a)

g cosec ∝

(b)

g

(c)

$\frac { g }{ tan\quad \alpha }$

(d)

g tan ∝

9. Dimensions of impulse are same as that of

(a)

Force

(b)

Momentum

(c)

Energy

(d)

Acceleration

10. A body is moving in a circle with uniform speed v. In moving from a point to another diametrically opposite point.

(a)

The momentum changes by mv

(b)

K.E. changes by 1/2mv2

(c)

The momentum changes by 2mv

(d)

K.E changes by mv2

11. A spacecraft of mass M moving with velocity v in free space explodes and breaks into two pieces. After the explosion a mass m of the spacecraft is left stationary. The velocity of  other part is

(a)

$\frac { mv }{ M-n }$

(b)

$\frac { M+n }{ Mv }$

(c)

$\frac { Mv }{ M-m }$

(d)

$\frac { Mv }{ m }$

12. Three blocks of masses 2 kg, 3 kg and 5 kg are connected to each other with light string & then placed on a frictionless surface. The system is pulled by a force F = 10N, then tension T1 is

(a)

1N

(b)

8N

(c)

5N

(d)

10N

13. If a reaction is R and coefficient of friction is μ, what is work done against friction in moving a body by distance d?

(a)

2 μRd

(b)

$\frac { \mu Rd }{ 4 }$

(c)

μRd

(d)

$\frac { \mu Rd }{ 2 }$

14. A particle is acted upon by a force of constant magnitude which is always perpendicular to the velocity of the particle. The motion of the particle takes place in the plane. It follows that

(a)

The speed of the particle is constant.

(b)

The motion is that of projectile.

(c)

The acceleration of the particle is constant.

(d)

The velocity of the particle is constant

15. The motion of a rocket is based on the principle of conservation of

(a)

Linear momentum

(b)

K.E

(c)

Mass

(d)

Angular momentum

16. A marble block of mass 3 kg lying on ice when given a velocity of 5 ms-1is stopped by friction in 10s. Then the coefficient of friction is

(a)

0.01

(b)

0.05

(c)

0.03

(d)

0.06

17. When milk is churned, cream gets separated due to

(a)

Centripetal force

(b)

Centrifugal force

(c)

Frictional force

(d)

Gravitational force

18. A body of mass 20 kg moving with a uniform velocity of 4 ms-1. Then the net force acting on a body is,

(a)

constant

(b)

increase

(c)

decrease

(d)

Zero

19. A force of 2.5 N acts on a body of mass 10 g. What is the acceleration of the body?

(a)

1.5 x 102 ms-2

(b)

2.0 x 103 ms-2

(c)

2.5 x 103 ms-2

(d)

3.0 x 102 ms-2

20. When a body is moving on a surface, the force of friction is called_____friction.

(a)

Static

(b)

Kinetic

(c)

Limiting

(d)

Rolling