#### 11th Standard Physics English Medium Free Online Test Volume 2 One Mark Questions 2020

11th Standard

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Physics

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

25 x 1 = 25
1. A planet moving along an elliptical orbit is closest to the Sun at distance r1 and farthest away at a distance of r2. If v1 and v2 are linear speeds at these points respectively. Then the ratio ${v_1\over v_2}$ is

(a)

${r_2\over r_1}$

(b)

$({r_2\over r_1})^2$

(c)

${r_1\over r_2}$

(d)

$({r_1\over r_2})^2$

2. A body is suspended from a spring balance kept in a satellite the reading of the balance is W1 when the satellite goes in an orbit of radius R and isW2 when it goes in an orbit of radius 2R

(a)

W1=W2

(b)

W1<W2

(c)

W1>W2

(d)

W1W2

3. Copper of fixed volume V is drawn into a wire of length l. When this wire is subjected to a constant force F, the extension produced in the wire is Δl. If Y represents the Young’s modulus, then which of the following graphs is a straight line?

(a)

$\Delta$l verses V

(b)

$\Delta$l  verses Y

(c)

$\Delta$l  verses F

(d)

$\Delta$l  verses $\frac{1}{l}$

4. Two fluids 1 and 2 have mass densities of P1 and P2 respectively. If P1> P2, which one of the following expressions will represent the relation between their specific volumes V1 and V2?

(a)

V1>V2

(b)

V12

(c)

V1=V2

(d)

cannot be determines

5. If the tension on a wire is removed at once, then _______.

(a)

it will break

(b)

its temperature will reduce

(c)

there will be no change in its temperature

(d)

its temperature will increase

6. When a fluid passes through the constricted part of a pipe, its _________.

(a)

velocity and pressure decrease

(b)

velocity and pressure increase

(c)

velocity decreases and pressure increases

(d)

velocity increases and pressure decreases

7. A gale blows over a house. The force due to the gale on the roof is ________.

(a)

in the downward direction

(b)

zero

(c)

in the upward direction

(d)

horizontal

8. If the surface tension of water is 0.06 Nm-1, then the capillary rise in a tube of diameter 1 mm is (angle of contact = 0°) _________.

(a)

1.22 cm

(b)

2.44cm

(c)

3.12cm

(d)

3.86 cm

9. In an adiabatic system which is true?

(a)

${ P }^{ \gamma }{ T }^{ \gamma -1 }$ = Constant

(b)

${ P }^{ \gamma }{ T }^{ 1-\gamma }$ = Constant

(c)

${ PT }^{ \gamma }$ = Constant

(d)

${ P }^{ 1-\gamma }{ T }^{ \gamma }$ = Constant

10. Which of the following will make the volume of an ideal gas four times?

(a)

double the absolute temperature and double the pressure

(b)

Halve the absolute temperature and double the pressure.

(c)

Quarter the absolute temperature at constant pressure.

(d)

Quarter the pressure at constant temperature.

11. An ideal gas is expanding such that PT2 = constant the coefficient of volume expansion of the gas is

(a)

$\frac{1}{T}$

(b)

$\frac{2}{T}$

(c)

$\frac{3}{T}$

(d)

$\frac{4}{T}$

12. An ideal gas heat engine operators in a carnot's cycle between 227°C and 127°C. It absorbs 6 x 104J at high temperature. The amount of heat converted into work is ________.

(a)

2.4 x 104J

(b)

4.8 x 104J

(c)

1.2 x 104J

(d)

6 x 104J

13. Two identically sized rooms A and B are connected by an open door. If the room A is air conditioned such that its temperature is 4° lesser than room B, which room has more air in it?

(a)

Room A

(b)

Room B

(c)

Both room has same air

(d)

Cannot be determined

14. The average K.E of a molecule.

(a)

is inversely proportional to the molecular mass of the gas.

(b)

is inversely proportional to the absolute temperature mass of the gas.

(c)

is directly proportional to the absolute temperature mass of the gas.

(d)

is not dependent on absolute temperature of the gas.

15. Ajar has mixture of hydrogen and Oxygen gases in the ratio 1 : 5. The ratio of mean kinetic energies of hydrogen and Oxygen molecules is ________.

(a)

1: 5

(b)

5: 1

(c)

1: 1

(d)

1: 25

16. At absolute zero temperature, the K.E. of the molecules becomes ________

(a)

zero

(b)

maximum

(c)

minimum

(d)

none of these

17. A loaded spring vibrates with a period T. The spring is divided into four equal parts and the same load is suspended from one as these parts. The new time period is _______

(a)

$\frac{T}{4}$

(b)

$\frac{T}{2}$

(c)

2 T

(d)

4 T

18. The equation of SHM of a particle is $\frac{d^2y}{dt^2}+ky=0$, where k is a positive constant. The time period of motion is given by _________.

(a)

$\frac{2\pi}{\sqrt k}$

(b)

$\frac{2\pi}{ k}$

(c)

$\frac{k}{2\pi}$

(d)

$\frac{\sqrt k}{2\pi}$

19. A body is executing simple harmonic motion with an angular frequency 2 rod/sec. The velocity of the body at 20mm displacement, when the amplitude of motion is 60mm, is

(a)

90 mm/s

(b)

113 mm/s

(c)

118 mm/s

(d)

131 mm/s

20. Which one of the following equations of motion represents simple harmonic motion?

(a)

Acceleration = - k0x+ k1x2

(b)

Acceleration = - k(x + a)

(c)

Acceleration = k(x + a)

(d)

Acceleration = kx

21. Consider two uniform wires vibrating simultaneously in their fundamental notes. The tensions, densities, lengths and diameter of the two wires are in the ratio 8 : 1, 1 : 2, x : y and 4 : 1 respectively. If the note of the higher pitch has a frequency of 360 Hz and the number of beats produced per second is 10, then the value of x : y is

(a)

36 : 35

(b)

35 : 36

(c)

1 : 1

(d)

1 : 2

22. The displacement y of a wave travelling in the x-direction is given by y = 10-4 sin (600t - 2x + $\pi\sqrt{3}$) Where is expressed in metres t is seconds, the speed of the wave motion(in ms-1) is

(a)

300

(b)

600

(c)

1200

(d)

200

23. The fractional change in wavelength of light coming from a star is 0.014%. What is its velocity?

(a)

4.2 x 103 m/s

(b)

3.8 x 108 m/s

(c)

3.5 x 103 m/s

(d)

4.2 x 104 m/s

24. The equation of a wave is y = 4 sin $\left\{ \frac { \pi }{ 2 } \left( 2t+\frac { x }{ 8 } \right) \right\}$where y, x are in em and t in seconds. The amplitude wavelength, velocity and frequency of the wave are, respectively _________.

(a)

4 cm, 32 cm, 16 cm/s, 0.5 Hz

(b)

8 cm, 16 cm, 32 cm/s, 1.0 Hz

(c)

4 cm, 32 cm, 32 cm/s, 0.5 Hz

(d)

8 cm, 16 cm, 16 cm/s, 1.0 Hz

25. Ultrasonic waves are those waves which _______.

(a)

human beings cannot hear

(b)

human beings can hear

(c)

have high velocity

(d)

have large amplitude