#### 11th Standard Physics Properties of Matter English Medium Free Online Test One Mark Questions 2020 - 2021

11th Standard

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Physics

Time : 00:20:00 Hrs
Total Marks : 20

20 x 1 = 20
1. If a wire is stretched to double of its original length, then the strain in the wire is

(a)

1

(b)

2

(c)

3

(d)

4

2. For a given material, the rigidity modulus is $\left( \frac { 1 }{ 3 } \right)$rd of Young’s modulus. Its Poisson’s ratio is

(a)

0

(b)

0.25

(c)

0.3

(d)

0.5

3. Two wires are made of the same material and have the same volume. Th e area of cross sections of the fi rst and the second wires are A and 2A respectively. If the length of the fi rst wire is increased by Δl on applying a force F, how much force is needed to stretch the second wire by the same amount?

(a)

2

(b)

4

(c)

8

(d)

16

4. Th e Young’s modulus for a perfect rigid body is

(a)

0

(b)

1

(c)

0.5

(d)

infinity

5. A certain number of spherical drops of a liquid of radius R coalesce to form a single drop of radius R and volume V. If T is the surface tension of the liquid, then

(a)

energy = 4 V T $\left( \frac { 1 }{ r } -\frac { 1 }{ R } \right)$is released

(b)

energy = 3 V T $\left( \frac { 1 }{ r } -\frac { 1 }{ R } \right)$is absorbed

(c)

energy = 3 V T $\left( \frac { 1 }{ r } -\frac { 1 }{ R } \right)$is released

(d)

energy is neither released nor absorbed

6. The wettability of a surface by a liquid depends primarily on

(a)

viscosity

(b)

surface tension

(c)

density

(d)

angle of contact between the surface and the liquid

7. An air bubble of diameter 4 mm rises steadily i through a solution of density 1500 kgm23 at the rate of 30cm-1 the coefficient of viscosity of the solution is

(a)

3.3 x 10-3 poise

(b)

2.2 x 10-3 poise

(c)

3.3 x 10-3 poise

(d)

4.4 x 10-3 poise

8. Steam at 100°C is passed into 20g of water at lOoCwhen water acquires a temp of 80°C, the mass of water present will be (take specifies heat of water 1 cal g-t c-1 & latent heat of steam= 540 cal g-1C-1)

(a)

42.5 g

(b)

22.5g

(c)

24g

(d)

31.5g

9. Two metal wires of identical dimensions are connected in series if σ1 and σ2 are the conductivity of the metal wire respectively, the effective conductivity of the combination is

(a)

$\frac{\sigma_{1}+\sigma_{2}}{2\sigma_{1}\sigma_{2}}$

(b)

$\frac{\sigma_{1}+\sigma_{2}}{\sigma_{1}\sigma_{2}}$

(c)

$\frac{\sigma_{1}\sigma_{2}}{(\sigma_{1}+\sigma_{2})}$

(d)

$\frac{2\sigma_{1}\sigma_{2}}{\sigma_{1}+\sigma_{2}}$

10. Water rises in a capillary tube to a certain height such that the upward force due to the surface tension is balanced by 62.84 x 10-5N force due to the weight of the liquid column. If the surface tension of water is 70 x 10-3Nm the radius of the capillary tube is

(a)

1.43 x 10-3m

(b)

2.83x 10-3 m

(c)

1.43x 10-2 m

(d)

2.83 x 10-3 m

11. Ablack body is continuously radiating ene.rlD' at a temperature of 2880 k if U1 U2 and U3 are the amount of radiation measured between the wavelengths 599 & 600 nm, 999 & 1000 nm & 1499& 1500nin respectively then (wiresconstant b = 2.88 x 1026 kmk)

(a)

U2 < U3

(b)

U1=U2=U3

(c)

U123

(d)

U2>U1>U3

12. If there were no gravity, which oftbe following will not be there for a fluid?

(a)

viscosity

(b)

surface tension

(c)

pressure

(d)

archimedes upward thrust

13. Critical velocity of the liquid

(a)

(b)

(c)

decreases when density increases

(d)

increase when density increases

14. A rectangular vessel when full of water, takes 10 min to be emptied through an orifice in its bottom, how much time will it take to be emptied when half filled with water

(a)

9 min

(b)

7 min

(c)

5 min

(d)

3 min

15. Two drops of equal radius coalesce to form a bigger drop. What is ratio of surface energy of bigger drop to smaller one?

(a)

21/2:1

(b)

1:1

(c)

22/3:1

(d)

none of these

16. Two capillaries of lengths L & 2L and of radii R & 2R are connected in series the net rate of flow of fluid through them will (rate of the flow through singe capillary,$x=\pi R^{4}/8 \eta L$)be

(a)

$\frac{8}{9}\alpha$

(b)

$\frac{9}{8}\alpha$

(c)

$\frac{5}{7}\alpha$

(d)

$\frac{7}{5}\alpha$

17. The water from a tap of diameter 1.25cm with a rate of 5 x 10-5 m3 s-1 the density & coefficient of viscosity of water are 103 kg m-3 & 10-3 pascal the flow of water is

(a)

(b)

turbulent with Reynold's number 5100

(c)

(d)

turbulent with Reynold's number 3900

18. The CGS unit of stress is,

(a)

N/m2

(b)

J/m2

(c)

dynl/cm2

(d)

N/cm2

19. Internal energy comprises of two types of energies, those are

(a)

mechanical and electrical energy

(b)

magnetic and electrical energy

(c)

kinetic and potential energy

(d)

kinetic and magnetic energy

20. Amount of energy required to change liquid to gas and vice versa without any change in temperature is termed as

(a)

Latent Heat and Fusion

(b)

Latent Heat of Yaporis ation

(c)

Heat capacity

(d)

Specific heat capacity