A Carnot engine having an efficiency of $\frac{1}{{10}}$ as heat engine, is used as a refrigerator. If the work done on the system is $10\;{\rm{ }}J,$ the amount of energy absorbed from the reservoir at lower temperature is

An ideal gas at ${27^ \circ }C$ is compressed adiabatically to $\frac{8}{{27}}$ of its original volume. If$\gamma = \frac{5}{3}$ , then the rise in temperature is

In an adiabatic process where pressure is increased by $\frac{2}{3}\% {\rm{if}}\frac{{{C_p}}}{{{C_v}}} = \frac{3}{2},$ then the volume decreases by about

Helium at ${27^ \circ }C$ has a volume of$8litres$. It is suddenly compressed to a volume of $1litre$. The temperature of the gas will be $\left[ {\gamma = 5/3} \right]$

A gas for which${\rm{\gamma }} = 1.5$ is suddenly compressed to the $\frac{1}{4}$ th of the initial volume. Then the ratio of the final to the initial pressure is

If an ideal gas is compressed isothermally then

An ideal gas at ${27^ \circ }C$ is compressed adiabatically to $\frac{8}{{27}}$ of its original volume. If$\gamma = \frac{5}{3}$ , then the rise in temperature is

The temperature inside a refrigerator is {t_2}{\,^{\rm{o}}}C and the room temperature is {t_1}{\,^o}C. The amount of heat delivered to the room for each joule of electrical energy consumed ideally will be

A lead bullet at ${27^{\rm{o}}}C$ just melts when stopped by an obstacle. Assuming that 25% of heat is absorbed by the obstacle, then the velocity of the bullet at the time of striking (M.P. of lead = ${327^{\rm{o}}}C\,$ , specific heat of lead = $0.03\,cal/g{}^{\rm{o}}C\,$, latent heat of fusion of lead = 6cal/g and J = 4.2joule/cal)

In which of the processes, does the internal energy of the system remain constant?

One mole of an ideal mono atomic gas is compressed isothermally in a rigid vessel to double its pressure at room temperature, ${27^0}C$. The work done on the gas will be