The resistance of a wire is $2.5 \Omega$ at a temperature 373 K . If the temperature coeffficient of resistance of the material of the wire is $3.6 \times 10^{-3} \mathrm{~K}^{-1}$, its resistance at a temperatrue 273 K is nearly.

When two identical resistors are connected in series to an ideal cell, the current through each resistor is 2 A . If the resistors are connected in parallel to the cell, the current through each resistor is

A conductor of length 1.5 m and area of cross-section $3 \times 10^{-5} \mathrm{~m}^2$ has electrical resistance of $15 \Omega$.

The current density in the conductor for an electric field of $21 \mathrm{Vm}^{-1}$ is

The relation between the current $i$ (in ampere) in a conductor and the time $t$ (in second) is $i=12 t+9 t^2$. The charge passing through the conductor between the times $t=2 \mathrm{~s}$ and $t=10 \mathrm{~s}$ is