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

11th Standard

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Physics

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

25 x 1 = 25
1. How many AU makes one metre?

(a)

3.26 x 1011AU

(b)

1.496 x 1011AU

(c)

3.08 x 1016 AU

(d)

6.684 x 10-12AU

2. Wllich pair do not have equal dimensions?

(a)

Energy and torque

(b)

Force and impulse

(c)

Angular momentum and Planck constant

(d)

Elastic modulus and pressure

3. The word physics is derived from the word_______

(a)

scientist

(b)

fusis

(c)

fission

(d)

fusion

4. If an object is dropped from the top of a building and it reaches the ground at t = 4 s, then the height of the building is (ignoring air resistance) (g = 9.8 ms-2)

(a)

77.3 m

(b)

78.4 m

(c)

80.5 m

(d)

79.2 m

5. What is the resultant vectors, when 2 vectors are at right angles to each other?

(a)

$R=\sqrt{P^2+Q^2}$

(b)

R=P+ Q

(c)

R=P-Q

(d)

$R=\sqrt \frac{P}{Q}$

6. Which of the following statements is/are not true?

(a)

v, a and s are vectors

(b)

Mass, energy, work are vectors

(c)

Vector has only magnitude whereas scalar has both magnitude and direction

(d)

both (b) and (c)

7. The expression for maximum height attained when the body is projected at an angle with the horizontal is:

(a)

$\frac{u\sin\theta}{2g}$

(b)

$\frac{u\sin^2\theta}{2g}$

(c)

$\frac{u^2\sin^2\theta}{g}$

(d)

$\frac{u^2\sin^2\theta}{2g}$

8. Spinning of the earth about its own axis is known as

(a)

linear motion

(b)

circular motion

(c)

curvilinear motion

(d)

rotational motion

9. In non-uniform circular motion, the resultant acceleration is given by

(a)

$a_R=\sqrt{a_t^2-(\frac{V^2}{r})^2}$

(b)

$a_R=\sqrt{a_t^2+(\frac{V^2}{r})^2}$

(c)

$a_R=\sqrt{a_t^2-(\frac{r}{V^2})^2}$

(d)

$a_R=\sqrt{a_t^2+(\frac{r}{V^2})^2}$

10. 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

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

(a)

Static

(b)

Kinetic

(c)

Limiting

(d)

Rolling

12. Which of the following is not an illustration of Newton's third law?

(a)

Flight of a jet plane

(b)

A cricket player lowering his hands while catching a cricket ball

(c)

Walking on floor

(d)

Rebouncing of a rubber plane

13. A body of mass M hits normally a rigid wall with velocity V and bounces back with the same velocity. The impulse experienced by the body is

(a)

MV

(b)

1.5 MV

(c)

2MV

(d)

zero

14. If a block of mass m lying on a frictionless inclined plane of length L, height h and angle of inclination $\theta$, then the time take taken to reach the bottom is

(a)

g sing $\theta$

(b)

sing $\theta$ $\sqrt { \frac { 2h }{ g } }$

(c)

sing $\theta$ $\sqrt { \frac { g }{ 2h } }$

(d)

$\frac { 1 }{ sin\ \theta } \sqrt { \frac { 2h }{ g } }$

15. Due to the action of internal forces of the system, the total linear momentum of the system is

(a)

a variable

(b)

a constant

(c)

always zero

(d)

always infinity

16. Identify which of the following energies can be positive only:

(a)

kinetic energy

(b)

potential energy

(c)

mechanical energy

(d)

both (a) and (b)

17. Same retarding force is applied to stop the train in certain distance. When the speed is doubled, how is this distance changed?

(a)

Remain same

(b)

Gets doubled

(c)

Gets doubled

(d)

Gets four times

18. Consider the following two statements.
(A) Linear momentum of a system of particles is zero
(B) Kinetic energy of a system of particles is zero. Then.

(a)

A does not imply. B and B does not imply A

(b)

A implies B but B does not imply A

(c)

A does not imply B but B implies A

(d)

A implies B and B implies A

19. A bullet is fired from a rifle which recoils after firing. The ratio of kinetic energy of the rifle to that of the bullet is:

(a)

less than one

(b)

more than one

(c)

equal to one

(d)

zero

20. In perfect inelastic collision, the relative velocity of the bodies:

(a)

before impact is zero

(b)

before impact is equal to that after impact

(c)

after impact is zero

(d)

None of the above is true

21. A stone tied to a piece of string whirled in a vertical circle with uniform speed, in what position of the stone is the tension in the string greatest?

(a)

in the highest position of the stone

(b)

in the lowest position of the stone

(c)

in the position when string is horizontal

(d)

is same for all positions of the stone

22. The efficiency of a heat engine working between the freezing point and boiling point of water is

(a)

6.25%

(b)

20%

(c)

26.8%

(d)

12.5%

23. A container has one mole of monoatomic ideal gas. Each molecule has f degrees of freedom. What is the ratio of $\gamma =\frac { { C }_{ p } }{ { C }_{ V } }$

(a)

f

(b)

$\frac{f}{2}$

(c)

$\frac{f}{f+2}$

(d)

$\frac{f+2}{f}$

24. A spring is connected to a mass m suspended from it and its time period for vertical oscillation is T. Th e spring is now cut into two equal halves and the same mass is suspended from one of the halves. Th e period of vertical oscillation is

(a)

T'= $\sqrt{2}$T

(b)

$T'=\frac { T }{ \sqrt { 2 } }$

(c)

T'=$\sqrt{2T}$

(d)

$T'=\sqrt { \frac { T }{ 2 } }$

25. The displacement y of a wave travelling in the x direction is given by y= (2 x10 -3) sin (300t -2x+$\frac{\pi}{4}$), where x and y are measured in metres and t in second. The speed of the wave is

(a)

150 ms-1

(b)

300 ms-1

(c)

450 ms-1

(d)

600 ms-1