The ratio of the average translational kinetic energies of hydrogen and oxygen at the same temperature is

When ' $n$ ' identical mercury drops combine to form a single big drop

The temperature of a body shown by a faulty Celsius thermometer is $49^{\circ} \mathrm{C}$ and by a correct Fahrenheit thermometer is $122^{\circ} \mathrm{F}$. The correction to be applied to the faulty thermometer is

If the radiation emitted by a perfect radiator has maximum intensity at a wavelength of $2900 \mathop {\rm{A}}\limits^{\rm{o}}$, the intensity of radiation emitted by it is

(Stefan-Boltzmann's constant $=5.67 \times 10^{-8} \mathrm{Wm}^{-2} \mathrm{~K}^{-4}$ and Wein's constant $=2.9 \times 10^{-3} \mathrm{mK}$ )