⚛️ Physics · Dual Nature of Radiation and Matter · NEET & JEE

An electron and a photon have the same momentum. If the photon has energy E, what is the kinetic energy of the electron in the non-relativistic limit?

Answer: E²/(2m_ec²).

A E
B E/2
C E²/(2m_ec²)
D 2E

Correct answer: C. E²/(2m_ec²)

Explanation: For the photon, p = E/c. For a non-relativistic electron, K = p²/(2m_e). Substituting p = E/c gives K = E²/(2m_ec²).

In the photoelectric setup, light striking the metal plate ejects electrons that cross the evacuated tube to the collector, producing a measurable current on the ammeter.

Concept context

Photoelectric effect, de Broglie waves, Bohr's model, atomic spectra.

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An electron and a photon have the same momentum. If the photon has energy E, what is the kinetic energy of the electron in the non-relativistic limit?

Concept context

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