The coefficient of performance of a refrigerator is $5$. If the temperature inside the freezer is $-20\,^{\circ}C$,the temperature of the surroundings to which it rejects heat is ....... $^{\circ}C$.

The potential energy of a diatomic molecule is given by $U = \frac{A}{r^{12}} - \frac{B}{r^6}$,where $A$ and $B$ are positive constants. The distance $r$ between them at equilibrium is:

The Thomson coefficient of a conductor is $10 \mu V/K$. The two ends of the conductor are maintained at $50^{\circ}C$ and $60^{\circ}C$,respectively. The amount of heat absorbed by the conductor when a charge of $10 C$ flows through it is:

If $f(x) = \frac{1}{\sqrt{x + 2 \sqrt{2x - 4}}} + \frac{1}{\sqrt{x - 2 \sqrt{2x - 4}}}$ for $x > 2$,then $f(11)$ is equal to

$A$ metal $M$ which is not affected by strong acids like conc. $HNO_3$,conc. $H_2SO_4$ and conc. solutions of alkalies like $NaOH$,$KOH$ forms $MCl_3$ which finds use for toning in photography. The metal $M$ is

$A$ light and a heavy body have equal kinetic energy. Which one has a greater momentum?