What is the time constant for the discharge of the capacitors in the figure (Figure 1) ?
Answer
\begin{aligned}
R_{e q}=\frac{R_{1} R_{2}}{R_{1}+R_{2}}=\frac{|x|}{1+1}=\frac{1}{2} k\Omega=0.5 \mathrm{k\Omega} \\
C=4 \mathrm{\mu f} \\
\end{aligned}
\begin{aligned}
\text { Time constant } \tau=R C=\operatorname{Ref} \times C \\
= & \left(0.5 \times 10^{3} \Omega\right)
\times\left(4 \times 10^{-6} \mathrm{~F}\right) \\
= & (5 \times 4) \times 10^{-4} \mathrm{~s} \\
= & 2 \times 10^{-3} \mathrm{~s} \\
= & 2 \mathrm{~ms}
\end{aligned}