Light Matter Interaction | MCQs

Explanation

To find the work function, we need to calculate the energy of the photon (E) and the kinetic energy of the electron (KE), then use the equation:

φ = E - KE

E = hc / λ = 1240 eV nm / 4000 nm = 3.1 eV

KE = (1/2)mv^2 ≈ (1/2) × 9.11 × 10^-31 kg × (6 × 10^5 m/s)^2 ≈ 1.64 × 10^-19 J ≈ 1.024 eV

φ = 3.1 eV - 1.024 eV ≈ 2.076 eV ≈ 2.1 eV

Explanation

The phenomenon where light of suitable frequency falling on a metal surface ejects electrons is called the "photoelectric effect."

Explanation

Einstein’s photoelectric equation is "hv = hvo + (1/2 mv^2) max", where:

• hv is the energy of the incident photon
• h is Planck's constant
• vo is the threshold frequency
• m is the mass of the emitted photoelectron
• max is the maximum kinetic energy of the emitted photoelectron.