Electrostatics ...

A resistor \'R\' and 2 µF capacitor in series is connected through a switch to 200 V direct supply. Across the capacitor is a neon bulb that lights up at 120 V. Calculate the value of R to make the bulb light up 5 s after the switch has been closed. (log₁₀ 2.5 = 0.4)

The figure shows an experimental plot discharging of a capacitor in an RC circuit. The time constant τ of this circuit lies between

Point charge q moves from point P to point S along the path PQRS (figure shown) in a uniform electric field E pointing coparallel to the positive direction of the X-axis. The co-ordinates of the points P, Q, R and S are (a, b, 0) (2a, 0, 0) (a, -b, 0) and (0, 0, 0) respectively, The work done by the field in the above process is given by the expression

The figure gives the electric potential V as a function of distance through five regions on x-axis. Which of the following is true for the electric field E in these regions

Which of the following graphs shows the variation of electric field E due to a hollow spherical conductor of radius R as a function of distance from the centre of the sphere

In a hollow spherical shell potential (V) changes with respect to distance (r) from centre

The electric field due to a uniformly charged sphere of radius R as a function of the distance from its centre is represented graphically by

Between the plates of a parallel plate capacitor a dielectric plate is introduced just to fill the space between the plates. The capacitor is charged and later disconnected from the battery. The dielectric plate is slowly drawn out of the capacitor parallel to the plates. The plot of the potential difference across the plates and the length of the dielectric plate drawn out is

During charging a capacitor variation of potential V of the capacitor with time t is shown as

Change Q on a capacitor varies with voltage V as shown in the figure, where Q is taken along the X-axis and V along the Y-axis. The area of triangle OAB represents