Three monochromatic sources having wavelengths 12.42 nm, 6.21 nm and 24.84 nm are placed close to each other in front of a converging lens such that equal powers from the three equal to 1mW each fall on a converging lens and then on a small spherical conductor of radius r = 1 mm and work function 62.1eV . (Assume 50% efficiency of emission and no change in effective value of work function due to photoelectric emission and potential rise) (Use hc = 1242 eV –nm) All electrons emitted by the sphere are immediately removed by some non-electrical mechanism). At t = 8s, switch S is closed, so that the sphere gets connected to the earth via a resistor of value 6.75  $M\Omega$. Find the current (in A) flowing just after the switch is closed.( Assume total power of the light is incident on sphere)