The figure shows an experimental plot for discharging of a capacitor in an R-C circuit. The time constant τ of this circuit lies between (a) 100 sec and 150 sec (b) 0 and 50 sec (c) 50 sec and 100 sec (d) 150 sec and 200 sec

Answer: (a). At t = τ, V = V₀/e = (25)/(2.718) ≈ 9.2 V. From the graph V ≈ 12.5 V at 100 s and ≈ 7.5 V at 150 s, so 9.2 V lies between them. So the answer is (a) 100 s and 150 s.

The figure shows an experimental plot for discharging of a capacitor… | JEE Main 2012 (AIEEE)

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Capacitors in DC Circuits & RC

The figure shows an experimental plot for discharging of a capacitor in an R-C circuit. The time constant $\tau$ of this circuit lies between

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Answer: (a)

At $t = \tau$ , $V = \dfrac{V_0}{e} = \dfrac{25}{2.718} \approx 9.2\text{ V}$ .
From the graph $V \approx 12.5\text{ V}$ at 100 s and $\approx 7.5\text{ V}$ at 150 s, so 9.2 V lies between them.
So the answer is (a) 100 s and 150 s.

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