Question

What is the time constant for the discharge of the capacitor? express your answer with the appropriate units?

Answer 1

The time constant for the discharge of a capacitor in a RC circuit is given by
$\tau = RC$
where R is the equivalent resistance of the circuit and C is the capacitance of the capacitor. The time constant corresponds to the time after which the charge on the capacitor has reduced to $e^{-1} \sim 36\%$ of the initial charge on the capacitor.

Since it is a time, the units of the time constant are seconds:
$[\tau]=[s]$