At $t=0$, capacitor is uncharged. If current through capacitor as function of time is $\frac{2V}{3R}{e}^{-\frac{2t}{NRC}}$ then find $N$_______

Consider the circuit shown in figure. The current flowing in the branch $cd$ is $\frac{E}{Nr}$, value of $N$ is_______

In the situation shown in figure, an ideal ammeter is connected across $7\Omega$ resistors. Select the correct statement from the following

What is the resistance of voltmeter shown in the circuit?

In the circuit shown below, the ammeter reading will be independent of $R_2$ when

In the meter bridge experiment, the null point is obtained at $N$. The value of unknown resistance $X$ will be