The average kinetic energy of hydrogen molecules at $300 K$ is $E.$ At the same temperature,the average kinetic energy of oxygen molecules will be

An electrolytic cell contains a solution of $Ag_2SO_4$ and has platinum electrodes. $A$ current is passed until $1.6 \ g$ of $O_2$ has been liberated at the anode. The amount of silver deposited at the cathode would be ............. $g$.

$CsBr_3$ contains

Photoelectric emission is observed from a metallic surface for frequencies $v_1$ and $v_2$ of the incident light rays $(v_1 > v_2)$. If the maximum values of kinetic energy of the photoelectrons emitted in the two cases are in the ratio of $1 : k$,then the threshold frequency of the metallic surface is

$A$ black body of mass $34.38 \ g$ and surface area $19.2 \ cm^2$ is at an initial temperature of $400 \ K$. It is allowed to cool inside an evacuated enclosure kept at a constant temperature of $300 \ K$. The rate of cooling is $0.04 \ ^{\circ}C/s$. The specific heat of the body in $J \ kg^{-1} \ K^{-1}$ is (Stefan's constant $\sigma = 5.73 \times 10^{-8} \ W \ m^{-2} \ K^{-4}$)

$A$ transverse wave is travelling along a stretched string from right to left. The figure shown represents the shape of the string at a given instant. At this instant,