2025 Exam Questions
Q. An electron, a proton, an \alpha -particle and a hydrogen atom are moving with the same kinetic energy. The associated de-Broglie wavelength will be longest for –
(A) proton
(B) electron
(C) hydrogen atom
(D) \alpha -particle
2024 Exam Questions
Q. Ifthe frequency of incident light falling on a photosensitive material is doubled, then kinetic energy of the emitted photoelectron will be____.
(a) the same as its initial value
(b) two times its initial value
(c) more than two times its initial value
(d) less than two times its initial value
Q. In photoelectric experiment, the stopping potential is1.5 V. What is the maximum kinetic energy of a photoelectron?
Q. Define photoelectric effect and explain the experimental set-up of photoelectric effect.
2023 Exam Questions
Q. If the maximum kinetic energy of emitted electrons in photoelectric effect is 2e V, the stopping potential will be____.
(A) 0.5 V
(B) 1.0 V
(C) 1.5 V
(D) 2.0 V
Q. With neat labelled circuit diagram, describe an experiment to study the characteristics of photoelectric effect.
Q. An electron is accelerated through a potential difference of 100 volt. Calculate de-Broglie wavelength in nm.
Q. State Einstein’s photoelectric equation and mention physical significance of each term involved in it.
Q. The wavelength of incident light is 4000 \AA . Calculate the energy of incident photon.
2022 Exam Questions
Q. Is it always necessary to use red light to get photoelectric effect?
Q. How does the wave theory of light fail to explain the observations from experiment on photoelectric effect? [Give any two points]
Q. What is de-Broglie hypothesis? Obtain the relation for de-Broglie wavelength.
Q. Explain de Broglie wavelength. Obtain an expression for de Broglie wavelength of wave associated with material particles.
Q. The photoelectric work function for a metal is 4.2 eV. Find the threshold wavelength.
