## PHYSICS

### PHYSICS

• 1 A.

SO2

B.

HCl

C.

CH4

D.

CO

• 2 A. B. C. D.

None of these

• 3

The number of equidistance oppositely charged ions in a sodium chloride crystal is

A.

2

B.

4

C.

6

D.

8

• 4 A. B. C. D. • 5

When an ideal gas undergoes unrestricted expansion, no cooling takes place because the molecules

A.

Exert no attractive forces on each other

B.

Do work equal to loss of KE

C.

Collide without loss of energy

D.

Are above the inversion temperature

• 6

If air contains N2 and O2 in volume ratio 4 ∶ 1. The average vapour density of air is:

A.

14.5

B.

16.5

C.

14.4

D.

29.0

• 7

Different gases at the same temperature have same

A.

Pressure

B.

Number of moles

C.

Volume

D.

Average kinetic energy

• 8

A gas at 298 K is shifted from a vessel of 250 cm3 capacity to that of 1 L capacity. The pressure of the gas will

A.

Becomes four times

B.

Becomes doubled

C.

Decrease by one-fourth

D.

Decrease by half

• 9

When a solid vaporizes directly without melting, it is known as:

A.

Evaporation

B.

Sublimation

C.

Sedimentation

D.

Saponification

• 10

The temperature of 20 L of nitrogen was increased from 10 K to 30 K at a constant pressure. Change in volume will be

A.

20 L

B.

40 L

C.

60 L

D.

80 L

• 11

The van der Waals’ equation for real gas is

A. B. C. D.

All of the above

• 12 A.

73 K

B.

100 K

C.

200 K

D.

510 K

• 13 A. B. C.

4

D.

1

• 14

Which phrase would be incorrect to use?

A.

A molecule of an element

B.

An atom of an element

C.

A molecule of a compound

D.

None of the above

• 15

The ratio of average speed of an oxygen molecule to the rms, speed of a nitrogen molecule at the same temperature is:

A. B. C. D. • 16

Which of the following represents total kinetic energy of one mole of gas?

A.

1/2 RT

B.

3/2 RT

C. D.

2/3 RT

• 17

At 27℃, 500 mL of helium diffuses in 30 min. What is the time (in hours) taken for 1000 mL of SO2 to
diffuse under same experimental conditions?

A.

240

B.

3

C.

2

D.

4

• 18

Space lattice of CaF2 is

A.

fcc

B.

Bcc

C.

hcp

D.

simple cubic

• 19

Which of the following gases would have the highest rms speed at 0℃ ?

A.

O3

B.

CO2

C.

SO3

D.

CO

• 20

Which one of the following metal oxides is antiferromagnetic in nature?

A.

MnO2

B.

VO2

C.

TiO2

D.

CrO2

• 21

Which gas contains larger number of molecules?

A.

4 g of H2O

B.

2 g of marsh gas

C.

4 g of PCl5

D.

2 g of phoszene

• 22

Assume that air is 21% oxygen and 79% nitrogen by volume. If the barometric pressure is 740 mm, the
partial pressure of oxygen is closest to which one of the following?

A.

155.4 mm

B.

310 mm

C.

580 mm

D.

740 mm

• 23

The maximum radius of sphere that can be fitted in the octahedral hole of cubical closed packing of sphere of radius ris

A.

0.732 r

B.

0.414 r

C.

0.225 r

D.

0.155 r

• 24

Identify the pair of gases that have equal rates of diffusion

A.

CO,NO

B.

N2O, CO

C.

N2O, CO2

D.

CO2,NO2

• 25

The following is not a function of an impurity present in a crystal

A.

Establishing thermal equilibrium

B.

Having tendency to diffuse

C.

Contributing to scattering

D.

Introducing new electronic energy levels