\[ E = \frac{E_0}{3} \implies V = \frac{V_0}{3} \]
\[ \frac{V_0}{3} = V_0 e^{-\frac{t}{\tau}} \]
\[ t = \tau \ln 3 \]
\[ 6.6 \times 10^{-6} = R (1.5 \times 10^{-6})(1.1) \]\[ R = \frac{6.6}{1.5} = 4 \, \Omega \]
A point charge $ +q $ is placed at the origin. A second point charge $ +9q $ is placed at $ (d, 0, 0) $ in Cartesian coordinate system. The point in between them where the electric field vanishes is:
A small bob of mass 100 mg and charge +10 µC is connected to an insulating string of length 1 m. It is brought near to an infinitely long non-conducting sheet of charge density \( \sigma \) as shown in figure. If the string subtends an angle of 45° with the sheet at equilibrium, the charge density of sheet will be :