# The Work Function for a Certain Metal is 4.2 Ev. Will this Metal Give Photoelectric Emission for Incident Radiation of Wavelength 330 Nm? - Physics

The work function for a certain metal is 4.2 eV. Will this metal give photoelectric emission for incident radiation of wavelength 330 nm?

#### Solution

No

Work function of the metal, phi_0 = 4.2 eV

Charge on an electron, = 1.6 × 10−19 C

Planck’s constant, h = 6.626 × 10−34 Js

Wavelength of the incident radiation, λ = 330 nm = 330 × 10−9 m

Speed of light, c = 3 × 108 m/s

The energy of the incident photon is given as:

E = "hc"/lambda

= (6.626 xx 10^(-34) xx 3 xx 10^8)/((330 xx 10^(-9)))   = 6.0 xx  10^(-19) J

= (6.0 xx 10^(-19))/(1.6 xx 10^(-19)) = 3.76 eV

It can be observed that the energy of the incident radiation is less than the work function of the metal. Hence, no photoelectric emission will take place.

Concept: Einstein’S Photoelectric Equation: Energy Quantum of Radiation
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#### APPEARS IN

NCERT Class 12 Physics Textbook
Chapter 11 Dual Nature of Radiation and Matter
Q 9 | Page 408