$6 \mu \mathrm{C}$ charge is placed at the centre of a cube. What will be the electric flux at each face of the cube?

$$ \left[\text { Take, } \frac{1}{4 \pi \varepsilon_0}=9 \times 10^9 \mathrm{~N}-\mathrm{m}^2 \mathrm{C}^2\right] $$

There are two thin wire rings, each of radius $R$, whose axes coincide. The charges of the rings are $q$ and $-q$. The magnitude of potential difference between the centres of the rings separated by a distance $\sqrt{3} R$ is

Statement I The temperature coefficient of resistance for most of metals in pure form is positive.

Statement II A metal wire 2 mm in diameter carries a charge of $360 \pi \mathrm{C}$ in two hours. If the metal contains $5 \times 10^{22}$ free electrons $/ \mathrm{cm}^3$, then drift velocity of the electrons in the wire is $6.25 \times 10^{10} \mathrm{~m} / \mathrm{s}$.

Statement III Semiconductors like pure germanium does not obey Ohm's law for all range of electric field values.

Which of the following is correct?

A cylindrical resistor of radius 7.0 mm and length 4.0 cm is made of material that has a resistivity of $10^{-6} \Omega-\mathrm{m}$. If the energy is dissipated at rate 1.54 W in the resistor, then the current density is