Light of two different frequencies whose photons have energies 1eV

Light Of Two Different Frequencies Whose Photons Have Energies 1 Physics Question

Light of two different frequencies whose photons have energies 1 eV and 2.5 eV respectively illuminate a metallic surface whose work function is 0.5 eV successively. Ratio of maximum speed of emitted electrons will be

Options

(a) 1 : 4
(b) 1 : 2
(c) 1 : 1
(d) 1 : 5

Correct Answer:

1 : 2

Explanation:

The maximum kinetic energy of emitted electrons is given by
K.E = WorkFunction(₀) – WorkFunction()
K.E₁ = 1 eV – 0.5 eV = 0.5 eV
K.E₂ = 2.5 eV – 0.5 eV = 2.0 eV
K.E₁ / K.E₂ = 0.5 eV / 2 eV = 1/4

KE = mv² /2
v₁ / v₂ = √1/4 = 1/2

Related Questions:

  1. A proton is moving in a uniform magnetic field B in a circular path of radius a
  2. Which one of the following is not a unit of young’s modulus?
  3. A radiotransmitter radiates 1 kW power at a wavelength 198.6 m. How many photons
  4. A black body at 227⁰C radiates heat at the rate of 7cals/cm²s. At a temperature
  5. A spring has time period T. It is cut into n equal parts. The time period of each part

Topics: Dual Nature of Matter and Radiation (150)
Subject: Physics (2479)

Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score

18000+ students are using NEETLab to improve their score. What about you?

Solve Previous Year MCQs, Mock Tests, Topicwise Practice Tests, Identify Weak Topics, Formula Flash cards and much more is available in NEETLab Android App to improve your NEET score.

NEETLab Mobile App

Share this page with your friends

Be the first to comment

Leave a Reply

Your email address will not be published.


*