Question

The work function of a metallic surface is 5.01 eV. The photoelectrons are emitted when light of wavelength 2000 Å falls on it. The potential difference applied to stop the fastest photoelectrons is [h = 4.14 x 10^-15 eV sec] ____________.

विकल्प

• 1.2 volts

• 2.24 volts

• 3.6 volts

• 4.8 volts

Answer 1

The work function of a metallic surface is 5.01 eV. The photoelectrons are emitted when light of wavelength 2000 Å falls on it. The potential difference applied to stop the fastest photoelectrons is 1.2 volts.

Explanation:

`"Energy of incident light E" = 12375/2000`

`= 6.18  "eV"`

`"According to relation E" = phi + "eV"_0, "we get"`

`"V"_0 = (E - phi)/e `

`= ((6.18  e"V" - 5.01  e"V"))/e`

`1.17  "V" approx 1.2  "V"`