Get Answers to all your Questions

header-bg qa

This question has Statement-1 and Statement-2. Of the four choices given after the statements, choose the one that best describes the two statements :

Statement - 1 : A metallic surface is irradiated by a monochromatic light of frequency  \upsilon > \upsilon _{0}  (the threshold frequency). The maximum kinetic energy and the stopping potential are K_{max}\; and V_{0}  respectively. If the frequency incident on the surface is doubled, both the   K_{max}\; and V_{0}  are also doubled.

Statement - 2 : The maximum kinetic energy and the stopping potential of photoelectrons emitted from a surface are linearly dependent on the frequency of incident light.

 

Option 1)

Statement-1 is true, statement-2 is false.

Option 2)

Statement-1 is true , Statement-2 is true, Statement-2 is the correct explanation of Statement-1.

Option 3)

Statement-1 is true , Statement-2 is true, Statement-2 is not the correct explanation of Statement-1.

Option 4)

Statement-1 is false, Statement-2 is true.

Answers (1)

best_answer

Aw we learnt in

Conservation of energy -

h\nu = \phi _{0}+\frac{1}{2}mv^{2}_{max}

h\nu = h\nu _{0}+\frac{1}{2}mv^{2}_{max}

 

h\left ( \nu-\nu _{0} \right )=\frac{1}{2}mv^{2}_{max}

where, h - Plank's constant\ \nu - Frequency\ \nu_{0} - threshold\ frequency\ \phi_{0}- work function

- wherein

 

 When frequency is doubled maximum kinetic energy and stopping potential become more than double.

K_{max}=eV_{0}=h{\nu}-h{\nu_{0}}                                (1)

So statement 1 is false.

Graph between maximum kinetic energy or stopping potential with frequency is linear.

So statement 2 is true.

Correct answer is 4.


Option 1)

Statement-1 is true, statement-2 is false.

This is an incorrect option.

Option 2)

Statement-1 is true , Statement-2 is true, Statement-2 is the correct explanation of Statement-1.

This is an incorrect option.

Option 3)

Statement-1 is true , Statement-2 is true, Statement-2 is not the correct explanation of Statement-1.

This is an incorrect option.

Option 4)

Statement-1 is false, Statement-2 is true.

This is the correct 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