The dimension of $\sqrt{\frac{\mu_0}{\epsilon_0}}$ is equal to that of (where $\mu_0 = \text{vacuum permeability}$ and $\epsilon_0 = \text{vacuum permittivity}$)

Which of the following graphs represents the variation of resistivity ( $\rho$ ) with temperature $(T)$ for copper?

What is the resistance of a cubic block of length $50 \, cm$ having a resistivity of $50 \times 10^{-8} \, \Omega m$?

What is the resistance between the rectangular faces of a block with resistivity $3 \times 10^{-7} \, \Omega \cdot m$ and dimensions $1 \, cm \times 1 \, cm \times 100 \, cm$?

The temperature coefficient of resistance of a conductor is:

The temperature coefficient of resistance at $0\,^{\circ}\text{C}$ is $\alpha = 0.00125\,^{\circ}\text{C}^{-1}$. At a temperature of $25\,^{\circ}\text{C}$,the resistance of a conductor is $1\,\Omega$. Find the temperature at which the resistance becomes $1.2\,\Omega$.