MCQ
In the transient current circuit shown, the time constant is
- A$\frac{5}{3}\,RC$
- B$\frac{5}{2}\,RC$
- ✓$\frac{7}{4}\,RC$
- D$\frac{7}{3}\,RC$
✓
Answer
Correct option: C.
$\frac{7}{4}\,RC$
c
$r_{e q}=\frac{R \times 3 R}{R+3 R}=\frac{3 R}{4}$
$r_{e q}=\frac{R \times 3 R}{R+3 R}=\frac{3 R}{4}$
$\mathrm{R}+\mathrm{r}_{\mathrm{eq}}=\mathrm{R}+\frac{3}{4} \mathrm{R}=\frac{7}{4} \mathrm{R}$
$\therefore $ time constant $=\frac{7}{4} \mathrm{RC}$
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