Question

19. The work function of a metal is 4.2eV. If radiation of 2000 A falls on the metal, then the
kinetic energy of the fastest photo electron is
1) 1.6 x 10-J 2) 16 x 10'
3) 3.2 x 10-J 4) 6.4 x 10-10​

Answer 1

Explanation:

Jehejejekekekeksjsse

Answer 2

answer is 3.2 × 10^-19 j

K.Emax = INCIDENT ENRGY - WORK FUNCTION

Incident energy = 12400/2000 = 6.2ev

Now

KE max = 6.2-4.2= 2ev

2 × 1.6 × 10 ^-19 j

3.2×10^-19 jo