Question

Light of wavelength 3500 Å is incident on two metal A & B whose work function are 4.2 eV& 1.9 eV respectively. Which metal will emit photo electron -

• A. A
• B. B
• C. Both A & B
• D. Neither A nor B

Answer 1

Answer: (C)

Both A & B

Answer 2

E =$\frac{hc}{\lambda}$= 3.55 eV E > f₁ & E > f₂