Answer: 43.
- A 1/√1836
- B 1/43
- C 1836
- D 43
Correct answer: D. 43
Explanation: For a particle of charge magnitude e accelerated through potential V, p = √(2meV). Hence λ = h/√(2meV), so λ is proportional to 1/√m. Therefore λe/λp = √(mp/me) = √1836 ≈ 43.
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.