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

Buy NEET English 2025-New Practice test pack

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 \(\frac { 1+60{ \gamma }_{ Hg } }{ 1+60{ \gamma }_{ Fe } } \)