#### 11th Standard Physics English Medium Free Online Test One Mark Questions with Answer Key 2020

11th Standard

Reg.No. :
•
•
•
•
•
•

Physics

Time : 00:25:00 Hrs
Total Marks : 25

25 x 1 = 25
1. If the length and time period of an oscillating pendulum have errors of 1% and 3% respectively then the error in measurement of acceleration due to gravity is

(a)

4%

(b)

5%

(c)

6%

(d)

7%

2. If a circle with 10 m radius and angle 60° at centre, then what will be the length of arc?

(a)

5.24m

(b)

6.21m

(c)

7.1 mm

(d)

10m

3. A ball is projected vertically upwards with a velocity v. It comes back to ground in time t. Which v-t graph shows the motion correctly?

(a)

(b)

(c)

(d)

4. Which of the following graph represents the equation y = mx + C?

(a)

(b)

(c)

(d)

5. Two blocks of masses m and 2m are placed on a smooth horizontal surface as shown. In the first case only a force F1 is applied from the left. Later only a force F2 is applied from the right. If the force acting at the interface of the two blocks in the two cases is same, then F1 :F2 is

(a)

1:1

(b)

1:2

(c)

2:1

(d)

1:3

6. A car when passes through a bridge exerts a force on it which is equal to

(a)

$mg+\frac { { Mv }^{ 2 } }{ r }$

(b)

$\frac { { Mv }^{ 2 } }{ r }$

(c)

$mg-\frac { { Mv }^{ 2 } }{ r }$

(d)

none

7. In a rocket, the fuel burns at the rate of 1kg s-1. This fuel burnt eject gases at a speed of 90 km s-1. The force exerted on the rocket is,

(a)

45000N

(b)

90000 N

(c)

60000 N

(d)

10000 N

8. A person sitting in an open car moving at constant velocity throws a ball vertically into air, the ball falls

(a)

exactly in the hand of thrower

(b)

outside the car

(c)

in the car ahead of the person

(d)

in the car behind the person

9. Inertia is that property of a body by virtue of which the body is:

(a)

unable to change by itself the state o frest

(b)

unable to change by itself the state of uniform motion

(c)

unable to change by itself the direction of motion

(d)

unable to change by itself the state of rest and ofunifonn linear motion

10. Which of the following force tends to stopthe moving object?

(a)

Frictional force

(b)

Magnetic force

(c)

Gravitational force

(d)

Electric force

11. For a car not to turn safely on a curved road:

(a)

speed is slow

(b)

distance between tyres is large

(c)

centre of gravity for car is low

(d)

low friction force

12. A body is moving with a constant speed v in a circle of radius r. Its angular acceleration is:

(a)

vr

(b)

$\frac { v }{ r }$

(c)

zero

(d)

$\frac { v }{ { r }^{ 2 } }$

13. An explosion breaks a rock into three parts in a horizontal plane. Two of them go off at right angles to each other. The first part of mass 1 kg moves with a speed of 12 ms-1 and the second part of mass 2 kg moves with 8 ms-1 speed. If the third part flies off with 4 ms-1 speed, then its mass is

(a)

7 kg

(b)

17 kg

(c)

3 kg

(d)

5 kg

14. The work done by the conservative force for a closed path is

(a)

always negative

(b)

zero

(c)

always positive

(d)

not defined

15. A rigid body rotates with an angular momentum L. If its kinetic energy is halved, the angular momentum becomes,

(a)

L

(b)

L/2

(c)

2L

(d)

L$\sqrt{2}$

16. The moment of inertia of a body about a given axis is 1.2 kgm2. Initially, the body is at rest. In order to produce a rotational kinetic energy of 1500 joule, an angular acceleration 25 radian/sec2 must be applied about that axis lor a duration of

(a)

4 s

(b)

2 s

(c)

8 s

(d)

10 s

17. Which of the following example does not constitute a couple?

(a)

steering a car

(b)

turning a pen cap

(c)

ball rolls on the floor

(d)

closing the door

18. The gravitational potential energy of the Moon with respect to Earth is

(a)

always positive

(b)

always negative

(c)

can be positive or negative

(d)

always zero

19. Energy required to move a body of mass 'M' from an orbit of radius 2R to 3R is =_________

(a)

$\frac{GM}{12R}$

(b)

$\frac{GMm}{3R^2}$

(c)

$\frac{GMm}{8R}$

(d)

$\frac{GMm}{6R}$

20. An artificial satellite is revolving round the Earth in a circular orbit, its velocity is half the eacape velocity. Its height from the Earth surface is _________ km.

(a)

6400

(b)

12800

(c)

3200

(d)

1600

21. A satellite is moving around the Earth with speed v in a circular orbit of radius r. If the orbit radius is decreased by 1% its speed will _______.

(a)

increase by 1%

(b)

increase by 0.5%

(c)

decrease by 1%

(d)

decrease by 0.5%

22. If a liquid wets a solid surface, the angle of contact is _________.

(a)

(b)

90°

(c)

less than°

(d)

greater than 90°

23. When you exercise in the morning, by considering your body as thermodynamic system, which of the following is true?

(a)

ΔU > 0, W > 0,

(b)

ΔU < 0, W > 0,

(c)

ΔU < 0, W < 0,

(d)

ΔU = 0, W > 0,

24. If the temperature and pressure of a gas is doubled the mean free path of the gas molecules

(a)

remains same

(b)

doubled

(c)

tripled

(d)

25. Pressure exerted by a gas is _______.

(a)

independent of the density of the gas

(b)

inversely proportional to the density of the gas

(c)

directly proportional to the density of the gas

(d)

directly proportional to the square of the density of the gas