The work function of a substance is 4.0 eV. The longest wavelength of light

The work function of a substance is 4.0 eV. The longest wavelength of light that can cause photoelectron emission from this substance is approximately

Options

(a) 540 nm
(b) 400 nm
(c) 310 nm
(d) 220 nm

Correct Answer:

310 nm

Explanation:

hc / λ(m) = Work function ⇒ λ(max) = hc / w

λ(max) = (6.6 x 10⁻³⁴) × (3 × 10⁸) / (4 × 1.6 × 10⁻¹⁹)

λ(max) = [(6.6 × 3) / (4 × 1.6)] × 10⁻⁷ m

λ(max) = 310 nm

admin:

Related Questions

  1. Monochromatic radiation emitted when electron on hydrogen atom
  2. A 1Ω resistance in series with an ammeter is balanced by 75 cm of potentiometer wire
  3. A force of 10 newton acts on a body of mass 20 kg for 10 seconds. Change in its momentum
  4. The magnetic susceptibility does not depend upon the temperature in
  5. If alpha, beta and gamma rays carry same momentum, which has the longest