A gas is compressed at a constant pressure of $$50 \mathrm{~N} / \mathrm{m}^2$$ from a volume of $$10 \mathrm{~m}^3$$ to a volume of $$4 \mathrm{~m}^3$$. Energy of $$100 \mathrm{~J}$$ is then added to the gas by heating. Its internal energy is

The reactance of capacitor at $$50 \mathrm{~Hz}$$ is $$5 \Omega$$. If the frequency is increased to $$100 \mathrm{~Hz}$$, the new reactance is

Stationary waves can be produced in

The pressure exerted by an ideal gas at a particular temperature is directly proportional to