Question

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

Answer 1

Explanation:

No

Work function of the metal, image077 NCERT Solutions class-12 physics Dual Nature of Radiation and Matter Part-1

Charge on an electron, e image078 NCERT Solutions class-12 physics Dual Nature of Radiation and Matter Part-1C

Planck’s constant, himage079 NCERT Solutions class-12 physics Dual Nature of Radiation and Matter Part-1Js

Wavelength of the incident radiation, image030 NCERT Solutions class-12 physics Dual Nature of Radiation and Matter Part-1= 330 nmimage080 NCERT Solutions class-12 physics Dual Nature of Radiation and Matter Part-1m

Speed of light, cimage081 NCERT Solutions class-12 physics Dual Nature of Radiation and Matter Part-1m/s

The energy of the incident photon is given as:

image035 NCERT Solutions class-12 physics Dual Nature of Radiation and Matter Part-1

image082 NCERT Solutions class-12 physics Dual Nature of Radiation and Matter Part-1

image083 NCERT Solutions class-12 physics Dual Nature of Radiation and Matter Part-1

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.