### NEET Physics - New - Behaviour of Perfect Gas and Kinetic Theory

#### Question - 1

A gas mixture consists of 2 moles of O2 and 4 moles of Ar at temperature T. Neglecting all vibrational modes, the total internal energy of the system is

• A 15 RT
• B 9 RT
• C 11 RT
• D 4 RT

#### Question - 2

The molecules of a given mass of a gas have r.m.s velocity of 200 m/s at 270C and 1.0 x 105 N/m2 pressure. When the temperature and pressure of the gas are respectively 127°C and 0.05 x 105Nm-2, the rms velocity of its molecules in ms-1 is

• A 100/3
• B 100$\sqrt{2}$
• C 400$\sqrt{3}$
• D 100$\sqrt { 2/3 }$

#### Question - 3

The ratio of specific heats Cp/Cv = $\gamma$ in terms of degree of freedom (n) is given by:

• A (1+n/3)
• B (1+2/n)
• C (1+n/2)
• D (1+ 1/n)

#### Question - 4

The mean free path of molecules of a gas (radius 'r') is inversely proportional to:

• A r3
• B r2
• C r
• D $\sqrt{r}$

#### Question - 5

Amonoatomic gas at a pressure P, having a volume V expands isothermally to a volume 2 V and then adiabatically to a volume 16 V. The final pressure of the gas is: (take $\gamma$ = 5/3)

• A 64 P
• B 32 P
• C P/64
• D 16 P

#### Question - 6

Liquid oxygen at 50 K is heated to 300 K at constant pressure of 1 atm. The rate of heating is constant. Which one of the following graphs represents the variation of temperature with time?

• A
• B
• C
• D

#### Question - 7

If Cp and Cv denote the specific heats (per unit mass) of an ideal gas of molecular weight M, then: where R is the molar gas constant

• A Cp-Cv = R/M2
• B Cp-Cv = R
• C Cp-Cv = R/M
• D Cp-Cv = M/R

#### Question - 8

Ratio specific heats of monoatomic molecule is:

• A $\gamma$=5/3
• B $\gamma$=3/5
• C $\gamma$=4/3
• D $\gamma$=2/3

#### Question - 9

A perfect gas at 27°C is heated at constant pressure to 3270C. If original volume of gas at 27°C is V then volume at 327° C is:

• A V
• B 3V
• C 2V
• D V/2

#### Question - 10

When a block of iron floats in mercury at 00C, fraction k1 of its volume is submerged, while at the temperature 60° C, a fraction k2 is seen to be submerged. If the coefficient of volume expansion of iron $\gamma$Fe and that of mercury is $\gamma$Hg, then the ratio k1/k2 can be expressed as

• A $(1+60{ \gamma }_{ Fe })/(1+60{ \gamma }_{ Hg })$
• B $\frac { 1-60{ \gamma }_{ Fe } }{ 1+60{ \gamma }_{ Hg } }$
• C $\frac { 1+60{ \gamma }_{ Fe } }{ 1-60{ \gamma }_{ Fe } }$
• D $\frac { 1+60{ \gamma }_{ Hg } }{ 1+60{ \gamma }_{ Fe } }$