In the given circuits (a) and (b) , switches S_ 1 and S_ 2 are...

In C-R series circuit,
$\text{q} = {\text{q}}_{0}\left(1 - \text{e}\dfrac{- t}{\text{τ}}\right)$
$⟹ \text{q} = \text{CE}\left(1 - \text{e}\dfrac{- \text{t}}{\text{RC}}\right)$
$∴ \text{I} = \dfrac{\text{d}\text{q}}{\text{d}\text{t}}$
$= \dfrac{\text{CE}}{\text{RC}}\left(+ \text{e}\dfrac{- \text{t}}{\text{RC}}\right)$
$\text{I} = \dfrac{\text{E}}{\text{R}}\text{e}\dfrac{- \text{t}}{\text{RC}}$
$⟹$ the urrent decays exponentially. In $L - R$ series circuit,
$\text{I} = {\text{I}}_{0} ( 1 - \text{e}\dfrac{- \text{t}}{\text{τ}} )$
$⇒ {\text{I}}_{0} = \dfrac{\text{E}}{\text{R}}$
$\text{⇒}\text{I} = \dfrac{\text{E}}{\text{R}}\left(1 - \text{e}\dfrac{- \text{Rt}}{\text{L}}\right)$
$⟹$ current grows exponentially.

$∴$ For $C - R$ circuit,



For $L - R$ circuit,