Find the Maximum Kinetic Energy of the Photoelectrons in Joules. - Physics


The photoelectric current in a photoelectric cell can be reduced to zero by a stopping potential of 1.8 volt. Monochromatic light of wavelength 2200Å is incident on the cathode. Find the maximum kinetic energy of the photoelectrons in joules. [Charge on electron = 1.6 x 10-19 C]



Given:- V0 = 1.8 V, e = 1.6 x 10-19 C, λ = 2200 Å

To find:- Maximim kinetic energy (K.E.)max

Formula:- (K.E.)max = eV0

Calculation: Using formula,

(K.E.)max = 1.6 x 10-19 x 1.8

∴ (K.E)max = 2.88 x 10-19 J

Maximum kinetic energy of emitted photoelectron is 2.88 x 10-19 J.

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2014-2015 (October)



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