Browse by Stream
QnA
Home
QnA
Go To Your Study Dashboard

Get Answers to all your Questions

header-bg qa
  • Home
  • Engineering
  • Solve it, Sodium and copper have work functions 2.3 eV and 4.5 eV respectively. Then the ratio of the wavelengths is nearest to

Sodium and copper have work functions 2.3 eV and 4.5 eV respectively. Then the ratio of the wavelengths is nearest to

Option 1)

1 : 2

 Option 2)

4 : 1
Option 3)

2 : 1

 Option 4)

1 : 4

Answers (1)

best_answer

As we learnt in

Work function -

Energy used to overcome the surface barrier and come out of metal surface.

\phi = h\nu _{0}

- wherein

h= Plank's \: constant

\nu _{0}= threshold \: frequency

 

 For electron to be ejected \frac{hc}{\lambda}={\phi}

Ratio of wavelength =\frac{h_{2}}{\lambda_{1}}=\frac{\phi_{1}}{\phi_{2}}

=\frac{\lambda_{sod}}{\lambda_{copp}}=\frac{\phi_{copper}}{\phi_{sodium}}=\frac{4.5}{2.3}\simeq2

Correct answer is 3


Option 1)

1 : 2

This is an incorrect option.

Option 2)

4 : 1

This is an incorrect option.

Option 3)

2 : 1

This is the correct option.

Option 4)

1 : 4

This is an incorrect option.

Posted by

perimeter

View full answer

JEE Main high-scoring chapters and topics

Study 40% syllabus and score up to 100% marks in JEE

Similar Questions

Trending Articles/News

anam-khan

JEE Main 2025: Hardwired to excel? Know BTech electrical engineering cut-offs at NITs
anam-khan

JEE Main 2025 chemistry needs conceptual understanding; 5 tips to score high
anam-khan

JEE Main 2025 exam city intimation slip for session 1 soon; paper pattern, exams from January 22

Latest Question