The temperature of $5$ moles of a gas at constant volume is changed from $100^{\circ} C$ to $120^{\circ} C$. The change in internal energy is $80 \ J$. The total heat capacity of the gas at constant volume in $J/K$ is:

The equation of the tangent to the curve $y = b e^{-x/a}$ at the point where it crosses the $y$-axis is:

The radius of ${}_{52}Te^{125}$ nucleus is $6 \text{ fermi}$. The radius of ${}_{13}Al^{27}$ nucleus in meters is

In a potentiometer experiment,the balancing length with a cell is $240\,cm$. On shunting the cell with a resistance of $2\,\Omega$,the balancing length becomes $120\,cm$. The internal resistance of the cell is ................... $\Omega$.

Two thin lenses of focal lengths $f_1$ and $f_2$ are in contact and coaxial. The power of the combination is

Values of the acceleration $A$ of a particle moving in simple harmonic motion as a function of its displacement $x$ are given in the table below. The period of the motion is

$A \; (mm \; s^{-2})$	$16$	$8$	$0$	$-8$	$-16$
$x \; (mm)$	$-4$	$-2$	$0$	$2$	$4$