A capacitor $C = 100$ $ \mu F$ is connected to three resistors each of resistance $1$ $kW$ and a battery of emf $9$ $V$. The switch $S $ has been closed for long time so as to charge the capacitor. When switch $S $ is opened, the capacitor discharges with time constant.....$ms$ 

If the distance between two equal point charge is doubled then what would happen to the force between them ?

In infinite long uniformly charged string is placed along $z-$ axis. Its linear charge density is $\lambda $. A point charge $q$ is moved from position $(a, 0, 0)$ to $(2a, 0, 0)$ then work done will be

Two point charges $+q$ and $-q$ are held fixed at $(-d, 0)$ and $(+d, 0)$ respectively of a $(x, y)$ coordinate system. Then

A particle of charge $Q$ and mass $m$ travels through a potential difference $V$ from rest. The final momentum of the particle is

In the circuit shown, a potential difference of $60\,V$ is applied across $AB$. The potential difference between the point $M$ and $N$ is.....$V$