Assertion: When a coil is joined to a cell, the current through the cell will be 10% less than its steady-state value at time $\mathrm{t} =\mathrm{\tau } {\log }_{\mathrm{e}} 10$, where $\mathrm{\tau }$ is the time constant of the circuit.

Reason: When a coil is joined to a cell, the growth of current is given by $\mathrm{i}={\mathrm{i}}_0{\mathrm{e}}^{-\mathrm{t}/\mathrm{\tau }}$

Assertion : The coil in the resistance boxes are made by doubling the wire.

Reason : Thick wire is required in resistance box.