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

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. The amount of work done by the centripetal force on the object moving in a circular path is

(a)

zero

(b)

infinity

(c)

positive

(d)

negative

3. The kinetic energy is not conserved in

(a)

Elastic collision

(b)

Inelastic collision

(c)

both (a) and (b)

(d)

none

4. For inelastic collision co-efficient of restitution is

(a)

0

(b)

1

(c)

0 < e < 1

(d)

$\infty$

5. If the momentum of a body increases by 25% its kinetic energy will increase by

(a)

25%

(b)

50%

(c)

125%

(d)

56.25%

6. A boy "A" of mass 50 kg climbs up a staircase in 10 s. Another boy "B" of mass 60 kg climbs up the same staircase in 15s. The ratio of the power developed by the boys "A" and "B" is

(a)

$\frac { 5 }{ 4 }$

(b)

$\frac { 3 }{ 2 }$

(c)

$\frac { 4 }{ 5 }$

(d)

$\frac { 2 }{ 3 }$

7. 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)

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

8. A couple produces____ motion.

(a)

linear and rotational

(b)

purely rotational

(c)

purely linear

(d)

no

9. Three identical spherical shells, each of mass m and radius r are placed as shown in.figure. Consider an axis xx1 which is touching to two shells and passing through diameter of third shell. M.I of the system consisting of these three spherial shells about xx1 axis is

(a)

3mr2

(b)

4mr2

(c)

16/5mr2

(d)

11/5 mr2

10. The ratio of the radii of gyration of a circular disc to that of circular ring, each of same mass and same radius about their axes is

(a)

$\sqrt{3}:\sqrt{2}$

(b)

$1:\sqrt{2}$

(c)

$\sqrt{2}:1$

(d)

$\sqrt{2}:\sqrt{3}$

11. Moment of inertia of a uniform solid cylinder about an axis passing through the center and along the axis of the cylinder is

(a)

MR2

(b)

M$\left( \frac { { R }^{ 2 } }{ 2 } +\frac { { l }^{ 2 } }{ 12 } \right)$

(c)

$\frac { 1 }{ 2 }$MR2

(d)

M$\left( \frac { { R }^{ 2 } }{ 4 } +\frac { { l }^{ 2 } }{ 12 } \right)$.

12. A solid floats in a liquid in a partially dipped position

(a)

The solid exerts a force equal to its weight on the liquid

(b)

The liquid exerts a force of buoyancy on the solid which is equal to the weight of the solid

(c)

The weight of the displaced liquid equals the weight of the solid

(d)

All the above

13. The force of viscosity is

(a)

electro magnetic

(b)

gravitational

(c)

nuclear

(d)

weak

14. What is an ideal fluid?

(a)

A fluid which has no viscosity

(b)

A fluid which is incompressible

(c)

A fluid which has no surface tension

(d)

All the above

15. The pressure in a water tap at the base of a building is 3 x 106 dynes/cm/ and on its top it is 1.6 x 106 dynes/cm2. The height of the building is approximately  __________.

(a)

7 m

(b)

14 m

(c)

70 m

(d)

140 m

16. The dimensional formula of coefficient of viscosity is ________.

(a)

M0 L-1 T-1

(b)

M0 L2 T-1

(c)

ML2 T-1

(d)

ML-1 T-1

17. Cv & C denote the molar specific heat capacities of a gas at constant volume and constant pressure then

(a)

Cp - Cv is larger for a diatomic ideal gas than for a monoatomic ideal gas

(b)

Cp, + Cv is larger for a diatomic ideal gas than for a monoatomic ideal gas

(c)

Cp, / Cv is larger for a diatomic ideal gas than for a monoatomic ideal gas

(d)

Cp, x Cv is lesser for a diatomic ideal gas than for a monoatomic ideal gas

18. An adiabatic process is one in which

(a)

the change in internal energy is equal to the mechanical work done

(b)

the temperature of the gas change

(c)

no heat enters or leaves the gas

(d)

all of the above

19. A perfect gas at 27°C is heated at constant pressure so as to double its volume. The temperature of the gas becomes.

(a)

54°C

(b)

150K

(c)

327°C

(d)

327K

20. Boyles' law is applicable in _______.

(a)

isochoric process

(b)

isothermal process

(c)

isobaric process

(d)

both (a) and (b)

21. One mole of gas occupies a volume of 200 ml. at 100 mm pressure. What is the volume occupied by two moles of this gas at 400 mm pressure and at same temperature?

(a)

50 ml

(b)

100 ml

(c)

200 ml

(d)

400 ml

22. The speeds of 5 molecules of a gas (in arbitrary units) are as follows: 2, 3, 4, 5, 6 The root mean square speed for these molecule is

(a)

2.91

(b)

3.52

(c)

4.00

(d)

4.24

23. In order to double the period of a simple pendulum _______.

(a)

its length should doubled

(b)

(c)

the mass of its bob should be doubled

(d)

the mass of its bob should be quadrupled.

24. The velocity of a particle, undergoing SHM is v at the mean position. If its amplitude is doubled, the velocity at the mean position will be  _______.

(a)

2 v

(b)

3v

(c)

2$\sqrt{2}v$

(d)

4v

25. Masses mA and mB hanging from the ends of strings of lengths IA and IB are executing. Simple harmonic motions. If their frequencies are related as fA= 2/B then ________.

(a)

IA= 2/B and mA= mB/2

(b)

IA = 4/B regardless of masses

(c)

lA = IB/4 regardless of masses.

(d)

IA = 2/B and mA = 2mB