If a gas is compressed isothermally then the r.m.s. velocity of the molecules
If a gas is compressed isothermally then the r.m.s. velocity of the molecules
remains the same.
increases.
decreases.
first decreases and then increases.
Solution
Root mean square (r.m.s) velocity of the molecules $\mathrm{v}_{\mathrm{rms}}=\sqrt{\frac{3 \mathrm{RT}}{\mathrm{M}}}$
$\Rightarrow \mathrm{v}_{\mathrm{rms}} \propto \sqrt{\mathrm{~T}}$
But in isothermal process, temperature remains constant. Thus the r.m.s velocity of the molecules remains constant.