Answer
(a) $17\Omega$
(b) $1.5ms$
Work Step by Step
(a) We know that
$R=\sqrt{\frac{L}{2C}}$
We plug in the known values to obtain:
$R=\sqrt{\frac{25\times 10^{-3}}{(2)(45\times 10^{-6})}}$
$R=17\Omega$
(b) The time constant RL can be determined as
$t=\frac{L}{R}$
We plugin the known values to obtain:
$t=\frac{25\times 10^{-3}}{16.67}$
$t=1.5ms$
