#### 11th Standard Physics English Medium Free Online Test Volume 1 One Mark Questions 2020

11th Standard

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Physics

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

25 x 1 = 25
1. The density of a material in CGS system of units is 4 g cm-3 . In a system of units in which unit of length is 10 em and unit of mass is 100 g, then the value of density of material will be

(a)

0.04

(b)

0.4

(c)

40

(d)

400

2. one parallactic second is,

(a)

3.08 x 1016 m

(b)

1.49 x 1011 m

(c)

9.46 x 1015 m

(d)

1.66 x 10-27 m

3. The same error repeated every time in the series of observation is known as _____________error.

(a)

random

(b)

constant

(c)

gross

(d)

systematic

4. One Angstrom is______

(a)

10-9 m

(b)

10-10 m

(c)

10-12 m

(d)

10-15 m

5. In a system of units, if force (F), acceleration (A) and time (T) are taken as fundamental units then the dimensional formula of energy is____________

(a)

[FA2T]

(b)

[FAT2]

(c)

[F2AT]

(d)

[FAT]

6. 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)

7. The distance covered by an object falling down freely under gravity in the last second of its motion is equal to the distance covered by it during the first five seconds of its motion. The time (in seconds) taken by the object to reach the ground is

(a)

8

(b)

5

(c)

13

(d)

10

8. The product of a vector with itself is equal to

(a)

0

(b)

1

(c)

$\infty$

(d)

A2

9. A book is at rest on the table which exerts a normal force on the book. If this force is considered as reaction force, what is the action force according to Newton's third law?

(a)

Gravitational force exerted by Earth on the book

(b)

Gravitational force exerted by the book on Earth

(c)

Normal force exerted by the book on the table

(d)

None of the above

10. 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 a plane. It follows that

(a)

Its acceleration is constant

(b)

Its velocity is constant

(c)

Its K.E. is contatnt

(d)

It moves in a straight line

11. A body of 2 kg acted upon by two forces each of magnitude 2 N, making. an angle of 60° with each other. The magnitude of net acceleration experienced by the body is

(a)

$\sqrt { 3 }$ms-2

(b)

2$\sqrt { 3 }$ms-2

(c)

5$\sqrt { 3 }$ms-2

(d)

3$\sqrt { 3 }$ ms-2

12. According to Newton's third law,

(a)

F12 = F21

(b)

F12 = - F21

(c)

F12 + F21 = 0

(d)

F12 $\times$ F21 = 0

13. Two masses 2 kg and 4 kg are tied at the ends of a massless string and which is passing over a frictionless pulley. The tension in the string is

(a)

3.68 N

(b)

78.4 N

(c)

26 N

(d)

13.26 N

14. A wind-powered generator converts wind U(x) energy into electric energy. Assume that the generator converts a fixed fraction of the wind energy intercepted by its blades into electrical energy. For wind speed v, the electrical power output will be proportional to,

(a)

v

(b)

v2

(c)

v3

(d)

v4

15. The law of conservation of energy always. holds good when:

(a)

a body moves down a rough plane

(b)

two electrically charged particles collide

(c)

two bodies collide

(d)

a body moves (or rolls) down a smooth plane

16. If $\vec F=(60\hat i+15\hat j-3\hat k)$N and $\vec v=(2\hat i-4\hat j+5\hat k)$ m/s, then instantaneous power is

(a)

195 watt

(b)

45 watt

(c)

75 watt

(d)

100 Watt

17. The speed of the center of a wheel rolling on a horizontal surface is vo  A point on the rim in level with the center will be moving at a speed of

(a)

zero

(b)

vo

(c)

$\sqrt{2}$vo

(d)

2vo

18. Two bodies of masses 2 kg and 3 kg have position vectors $\hat { i } +2 \hat { j} +\hat { k}$ and $\hat { -4i } - \hat {-3jj} +\hat { 6k}$ respectively. The centre of mass of this system has a position vector.

(a)

$\hat {- 3i } -\hat { j}$

(b)

$\hat {5 i } - \hat { j} +2\hat { k}$

(c)

$\hat {-2 i } - \hat { j} +4\hat { k}$

(d)

$\hat { -3i } - \hat { j} +\hat7 { k}$

19. Centre of mass of a body practically coincides with:

(a)

its centre of gravity

(b)

its centre of buoyancy

(c)

orthocenter

(d)

metacentre

20. The angular momentum of a moving body remains constant, if:

(a)

net external force is applied

(b)

net pressure is applied

(c)

net external torque is applied

(d)

net external torque is not applied

21. A body cannot roll without slipping on a:

(a)

rough horizontal surface

(b)

smooth horizontal surface

(c)

rough inclined surface

(d)

smooth inclined surface

22. Two discs of same material have the same mass. If their thicknesses are in the ratio 1:3, then their moments of inertia are in the ratio

(a)

3:1

(b)

1:3

(c)

1:9

(d)

$1:\sqrt{3}$

23. The work done by the torque is

(a)

F.ds

(b)

F.dθ

(c)

ፒdθ

(d)

r.dθ

24. When a solid sphere is undergoing pure rolling, the ratio of translational kinetic energy to rotational kinetic energy is

(a)

2:5

(b)

5:2

(c)

1:5

(d)

5:1

25. Moment of inertia of a thin uniform ring about an axis passing through the center of gravity and perpendicular to the plane is

(a)

MR2

(b)

2 MR2

(c)

$\frac { 1 }{ 2 }$MR2

(d)

$\frac { 3 }{ 2 }$MR2