Which of the following statements are correct?
A. The matter wave picture could not incorporate the Heisenberg's uncertainty principle.
B. The wave properties of electrons have been utilised in the design of electron microscope.
C. Electron diffraction experiments have verified and confirmed the wave nature of electrons.
D. Photons are not deflected by magnetic fields.
E. The photon energy is dependent on intensity of radiation.
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → B, C and D only
Each statement is judged against the wave-particle duality of matter and radiation.
(A) The matter wave picture could not incorporate the Heisenberg's uncertainty principle — Incorrect. The matter wave picture does incorporate it. A wave of one definite wavelength (definite momentum) is spread over all space, and a particle confined to a small region needs a group of waves of different wavelengths, which means a spread in momentum: \( \Delta x\,\Delta p \gtrsim \hbar \).
(B) The wave properties of electrons have been utilised in the design of electron microscope — Correct. Fast electrons have a very short de Broglie wavelength, so the microscope resolves far finer detail than light can.
(C) Electron diffraction experiments have verified and confirmed the wave nature of electrons — Correct. The Davisson–Germer experiment and G. P. Thomson's experiment showed diffraction of electrons by crystals, which only waves can show.
(D) Photons are not deflected by magnetic fields — Correct. A photon carries no charge, so the magnetic force \( q\,\vec{v}\times\vec{B} \) on it is zero.
(E) The photon energy is dependent on intensity of radiation — Incorrect. The energy of a photon is \( E = h\nu \) and depends only on the frequency. The intensity decides how many photons arrive per second.
Note: Statements (D) and (E) of this question are from the latest textbook (2026-27). Statements (A), (B) and (C), on the uncertainty principle, the electron microscope and electron diffraction, are printed only in the pre-rationalised textbook (2022-23). They were removed from the latest book, and they also appear to be out of the CUET 2026 syllabus.
NCERT (2026-27):
Particle Nature of Light: The Photon – “… Thus, photon energy is independent of intensity of radiation. (iv) Photons are electrically neutral and are not deflected by electric and magnetic fields.”
NCERT (Pre-rationalised edition, 2022-23):
Wave Nature of Matter – “… The matter–wave picture elegantly incorporated the Heisenberg’s uncertainty principle.”
Davisson and Germer Experiment – “… The wave properties of electrons have been utilised in the design of electron microscope which is a great improvement, with higher resolution, over the optical microscope.”
Summary – “… 10. Electron diffraction experiments by Davisson and Germer, and by G. P. Thomson, as well as many later experiments, have verified and confirmed the wave-nature of electrons.”