Free account: track your progress — Sign up free

WAEC Physics 2020 Objective — Question 29

Question 29 of 50 from the West African Examinations Council (WAEC) Physics 2020 Objective paper, with the correct answer and a full explanation.

Advertisement

Which of the following statements about photoelectrons is correct?

  • A. A faint green light produces photoelectrons with less kinetic energy than a bright red light
  • B. A red light releases a smaller number of electrons than a green light
  • C. A faint green light produces photoelectrons with greater kinetic energy than a bright red lightCorrect
  • D. A red light produces more photoelectrons than a green light

Explanation

A faint green light has a lower wavelength and hence higher photon energy than a bright red light; thus it produces photoelectrons with greater kinetic energy than a bright red light, though fewer in number since it's fainter (lower intensity).

Advertisement

Sign up free to unlock

  • Score tracking
  • Practice history
  • Saved questions
  • Progress dashboard
  • Personalized sessions
  • Weak-topic breakdown

…and/or go further with premium services and No Ads.