Same chapter3 marksDifficulty: Medium
Light of frequency 1015 Hz falls on a metal of work function 2 eV. Find the maximum kinetic energy of the photoelectrons. Take h = 6.63 × 10−34 J s.
Dual Nature of Radiation and Matter
3 marksDifficulty: Medium
The work function of a metal is 2 eV. Find the threshold wavelength. Take h = 6.63 × 10−34 J s and c = 3 × 108 m s−1.
Original Khojo Papers practice question — not from a past board paper.
Answer
About 621 nm
No citable source has been recorded for this record. Treat it as practice material, not as fact.
Explanation
The threshold frequency is ν0 = φ0/h, so λ0 = hc/φ0 = (6.63 × 10−34 × 3 × 108) ÷ (2 × 1.6 × 10−19) ≈ 6.2 × 10−7 m.
Related questions
From the same topic and chapter, at a similar level.
Same chapter3 marksDifficulty: Medium
What is stopping potential, and how does it depend on the intensity and the frequency of the incident light?
Dual Nature of Radiation and Matter
Same chapter3 marksDifficulty: Medium
State the laws of the photoelectric effect and write Einstein's photoelectric equation.
Dual Nature of Radiation and Matter
Same chapter3 marksDifficulty: Medium
State the de Broglie hypothesis and give the expression for the wavelength of a moving particle.
Dual Nature of Radiation and Matter
Same subject3 marksDifficulty: Medium
State Kirchhoff's two laws and say what conservation principle each expresses.
Current Electricity
Same subject3 marksDifficulty: Medium
Two capacitors of 2 μF each are joined in series and then in parallel. Find the equivalent capacitance in each case.
Electrostatics