Browse by Stream
QnA
Home
QnA
Go To Your Study Dashboard

Get Answers to all your Questions

header-bg qa
  • Home
  • NCERT
  • Light of frequency 7.21 × 10^14 Hz is incident on a metal surface. Electrons with a maximum speed of 6.0 × 10^5 m/s are ejected from the surface. What is the threshold frequency for photoemission of electrons?

Q: 11.10  Light of frequency 7.21\times 10^1^4\hspace{1mm}Hz  is incident on a metal surface. Electrons with a  maximum speed of  6.0\times 10^5\hspace{1mm}m/s are ejected from the surface. What is the threshold  frequency for photoemission of electrons? 

Answers (1)

best_answer

The energy of incident photons is E given by

\\E=h\nu \\ E=6.62\times 10^{-34}\times 7.21\times 10^{14}\\ E=4.77\times 10^{-19}\ J

Maximum Kinetic Energy of ejected electrons is

\\KE_{max}=\frac{1}{2}mv^{2}\\ KE_{max}=\frac{9.1\times 10^{-31}\times (6\times 10^{5})^{2}}{2} \\KE_{max}=1.64\times 10^{-19}\ J

Work Function of the given metal is

\phi _{0}=E-KE_{max}=3.13\times 10^{-19}\ J

The threshold frequency is therefore given by

\\\nu _{0}=\frac{\phi _{0}}{h}\\ \nu _{0}=4.728\times 10^{14}\ Hz

Posted by

Sayak

View full answer

Crack CUET with india's "Best Teachers"

  • HD Video Lectures
  • Unlimited Mock Tests
  • Faculty Support
cuet_ads

Similar Questions

Trending Articles/News

anam-khan

CBSE Board Exams 2025: Guidelines issued for Class 10, 12 practicals
anam-khan

Board Exam Date Sheet 2025 Live: ICSE, ISC, CBSE, MP time table out; BSEB routine soon
anam-khan

Board exam dates 2025: CBSE, CISCE, UP, MP, Maharashtra, TN time table out; state-wise updates

Latest Question