Paper 1 Thermal Physics B Drills

Q1

An ideal gas molecule is assumed to have collisions that are

A. perfectly elastic.
B. perfectly inelastic.
C. impossible.
D. always nuclear.

Q2

Ideal gas pressure is caused by molecules

A. sticking to the wall.
B. colliding with walls and changing momentum.
C. being at rest.
D. losing charge.

Q3

For an ideal gas, mean translational kinetic energy per molecule is

A. $\frac{1}{2}kT$.
B. $\frac{3}{2}kT$.
C. $3RT$.
D. $pV$.

Q4

The equation $pV=nRT$ requires $T$ in

A. Celsius.
B. kelvin.
C. pascal.
D. joule.

Q5

Number of molecules in $n$ moles is

A. $n/N_A$.
B. $n{N}_A$.
C. $N_A/n$.
D. $nR$.

Q6

At constant temperature for a fixed amount of ideal gas, $pV$ is

A. constant.
B. proportional to $V^2$.
C. zero.
D. negative.

Q7

Internal energy of an ideal gas depends only on

A. volume.
B. pressure alone.
C. temperature.
D. container shape.

Q8

Using convention $\Delta U=Q+W_{on}$, adiabatic compression has

A. $Q=0$, $W_{on}>0$, $\Delta U>0$.
B. $Q>0$, $W_{on}=0$.
C. $Q=0$, $W_{on}<0$.
D. $\Delta U=0$ always.

Q9

For constant-volume heating of a gas, boundary work is

A. positive.
B. negative.
C. zero.
D. infinite.

Q10

Area under a p-V graph represents

A. work done by gas for expansion convention.
B. temperature only.
C. momentum.
D. charge.

Q11

In an isothermal change of an ideal gas, internal energy change is

A. zero.
B. always positive.
C. always negative.
D. equal to pressure.

Q12

A mole is an amount containing

A. $6.02\times 10^{23}$ entities.
B. $9.81$ entities.
C. one kilogram always.
D. one pascal always.

Q13

The rms speed of ideal gas molecules increases when

A. temperature increases.
B. volume increases at fixed temperature.
C. mass of container increases.
D. pressure is zero only.

Q14

For a fixed amount of gas at constant pressure, increasing kelvin temperature makes volume

A. increase proportionally.
B. decrease proportionally.
C. unchanged always.
D. negative.

Q15

The first law is essentially conservation of

A. energy.
B. charge.
C. wavelength.
D. refractive index.

Q16

Heat supplied to a gas is

A. a state property.
B. energy transfer due to temperature difference.
C. always equal to internal energy.
D. always zero.

Q17

Work done by a gas during expansion at constant pressure is

A. $p\Delta V$.
B. $p/\Delta V$.
C. $\Delta V/p$.
D. $nR{T}^2$.

Q18

In a cyclic process, the net change in internal energy is

A. zero.
B. equal to total volume.
C. always positive.
D. undefined.

Q19

The assumption of random molecular motion leads to

A. equal mean square components in three perpendicular directions.
B. all molecules moving in one direction.
C. zero pressure.
D. no wall collisions.

Q20

A real gas is closest to ideal when

A. low pressure and high temperature.
B. high pressure and low temperature.
C. liquefying.
D. molecular volume dominates.