The potential difference across the ends of conductor is $\beta 0 \pm 03) \mathrm{V}$ and the current through the conductor is $(5 \pm 0.10)$ A. The error in the determination of the resistance of the conductor is

If $E_1=4 \mathrm{~V}$ and $E_2=12 \mathrm{~V}$, the current in the circuit and potential difference between the points $P$ and $Q$ respectively are

Two identical cells gave the same current through an external resistance of $2 \Omega$ regardless whether the cells are grouped in series or parallel. The internal resistance of the cells is

The charge $q$ (in coulomb) passing through a $10 \Omega$ resistor as a function of time $t$ (in second) is given by $q=3 t^2-2 t+6$. The potential difference across the ends of the resistor at time $t=5 \mathrm{~s}$ is