When a certain photosensitive surface is illuminated with monochromatic light of frequency v, the stopping potential for the current is –V₀/2. When the surface is illuminated by monochromatic light of frequency v/2, the stopping potential is – V₀. The threshold frequency for photoelectric emission is :

An ideal gas is enclosed in a cylinder at pressure of 2 atm and temperature 300 K. The mean time between two successive collisions is 6 $$ \times $$ 10^–8 s. If the pressure is doubled and temperature is increased to 500 K, the mean time between two successive collisions will be close to

A load of mass M kg is suspended from a steel wire of length 2m and radius 1.0 mm in Searle's apparatus experiment. The increase in length produced in the wire is 4.0 mm. Now the load is fully immersed in a liquid of relative density 2. The relative density of the material of load is 8.

The new value of increase in length of the steel wire is:

The charge on a capacitor plate in a circuit, as a function of time, is shown in the figure :


When is the value of current at t = 4 s ?