Practicing Success

Target Exam

CUET

Subject

Physics

Chapter

Electrostatic Potential and Capacitance

Question:

Options:

a

b

c

d

Correct Answer:

b

Explanation:

$ V_C = 200(1 - e^\frac{-t}{\tau}) = 120$

$\Rightarrow e^\frac{-t}{\tau} = 0.4 $

$\Rightarrow \frac{t}{\tau} = ln 2.5 = 0.92$

$ \tau = \frac{5}{0.92} = RC$

$\Rightarrow R = \frac{5}{0.92\times 2 \times 10^{-6}} = 2.7 \times 10^6 \Omega$