$A$ cell of emf $1.8 \ V$ gives a current of $17 \ A$ when directly connected to an ammeter of resistance $0.06 \ \Omega$. The internal resistance of the cell is: (in $\Omega$)

Find the equivalent resistance across $AB$ in the given circuit.

Two resistances $R_1$ and $R_2$ are made of different materials. The temperature coefficient of the material of $R_1$ is $\alpha$ and of the material of $R_2$ is $-\beta$. The resistance of the series combination of $R_1$ and $R_2$ will not change with temperature,if $R_1/R_2$ equals

Two wires of resistances $R_1$ and $R_2$ have temperature coefficients of resistance $\alpha_1$ and $\alpha_2$ respectively. If these are joined in series,the effective temperature coefficient of resistance is:

In the given circuit,the potentials at points $B$,$C$,and $D$ will be:

In a copper voltameter,the mass deposited in $30\, \text{s}$ is $m\, \text{g}$. If the current-time graph is as shown in the figure,the Electrochemical Equivalent $(ECE)$ of copper is: