The current in a wire varies with time according to the equation $I=(4+2t),$ where $I$ is in ampere and $t$ is in seconds. The quantity of charge which has passed through a cross-section of the wire during the time $t=2$ s to $t=6$ s will be:

A charged particle having drift velocity of $7.5\times10^{-4}~\text{ms}^{-1}$ in an electric field of $3\times10^{-10}~\text{Vm}^{-1},$ has mobility of: 
1. $2.5\times 10^{6}~\text{m}^2\text{V}^{-1}\text{s}^{-1}$
2. $2.5\times 10^{-6}~\text{m}^2\text{V}^{-1}\text{s}^{-1}$
3. $2.25\times 10^{-15}~\text{m}^2\text{V}^{-1}\text{s}^{-1}$
4. $2.25\times 10^{15}~\text{m}^2\text{V}^{-1}\text{s}^{-1}$

Drift velocity $v_d$ varies with the intensity of the electric field as per the relation:
1. $v_{d} \propto E$
2. $v_{d} \propto \frac{1}{E}$
3. $v_{d}= \text{constant}$
4. $v_{d} \propto E^2$

The resistance of a wire is $R$ ohm. If it is melted and stretched to $n$ times its original length, its new resistance will be:

Two solid conductors are made up of the same material and have the same length and the same resistance. One of them has a circular cross-section of area $𝐴 _1$ and the other one has a square cross-section of area $A_2.$ The ratio of $𝐴 _1 / 𝐴 _2$ is:

The dependence of resistivity $(\rho)$ on the temperature $(T)$ of a semiconductor is, roughly, represented by:

1.		2.
3.		4.

The equivalent resistance between $A$ and $B$ for the mesh shown in the figure is:

A potential divider is used to give outputs of $2~\text{V}$ and $3~\text{V}$ from a $5~\text{V}$ source, as shown in the figure.

In the circuit shown in the figure, the effective resistance between $A$ and $B$ is:

1. $2~\Omega$
2. $4~\Omega$
3. $6~\Omega$
4. $8~\Omega$

The effective resistance between points $P$ and $Q$ of the electrical circuit shown in the figure is: