A monoatomic ideal gas is compressed adiabatically to $\left(\frac{1}{27}\right)$ of its initial volume. If initial temperature of the gas is ' T ' K and final temperature is ' xT ' K , the value of ' x ' is

In LCR series circuit, when ' $L$ ' is removed from the circuit, the phase difference between voltage and current in the circuit is $\frac{\pi}{3}$. If ' $C$ ' is removed from the circuit instead of $L$ then phase difference is again $\frac{\pi}{3}$. The power factor of the circuit is $\left(\tan 60^{\circ}=\sqrt{3}\right)$

The value of the shunt resistance that allows $10 \%$ of the main current through the galvanometer of $99 \Omega$ is

In which of the following figures, the p.n. junction diode is reverse biased?