Two cylinders A and B fitted with pistons contain equal amount of an ideal diatomic gas at 303 K. The piston of cylinder A is free to move and that of cylinder B is held fixed. The same amount of heat is given to the gas in each cylinder. If the rise in temperature of the gas in cylinder B is 63 K then the rise in temperature of the gas in A is

The temperature at which r.m.s. velocity of hydrogen molecules is 4.5 times that of an oxygen molecule at $47^\circ$ C is (molecular weight of hydrogen and oxygen are 2 and 32 respectively)

In an external environment of temperature ($T$) kelvin, a sphere at temperature ($3T$) kelvin has cooling rate $R_1$. When the temperature of that sphere falls to ($2T$) kelvin, the cooling rate $R_2$ of the sphere will become

'$x$' joule of heat is incident on a body. Out of it, the total heat reflected and transmitted by it is '$y$' joule. The absorption coefficient of the body is