Question

The photoelectric work function for a metal is 4.2 eV. If the stopping
potential is 3 V, find the threshould wavelength and the maximum kinetic
energy of emitted electron.​

Answer 1

Answer:

Explanation:

HERE ,

GIVEN ,WORKFUNCTION(ω) =4.2ev

STOPPING POTENTIAL(V0

) =3V

SO WE KNOW THAT ,

THE THRESOLD WAVELENGTH =hc / ω

LAMBDA(THRESOLD WAVELENGTH)= 6.626×10^-34  ×   3×10^8 /  4.2 ×1.6 ×10^-19

=83.4876× 10^-7 METER

ALSO WKT ,KE(MAX) =eV0

SO KE(MAX)= 1.6×10^-19 ×  4.2 ×1.6 ×10^-19

=10.752 ×10^-38 JOULE