Question

Lights of two different frequencies, whose photons have energies 1 eV and 2.5 eV respectively, successively illuminate a metal whose work function is 0.5 eV. The ratio of the maximum speeds of the emitted electrons will be

(a) 1 : 5

(b) 1 : 4

(c) 1 : 2

(d) 1 : 1

Answer 1

Correct option: (c) 1 : 2

Explanation:

Einstein equation KEmax = E – Work function;

1/2 mv2= E - W

Using this concept,