COMEDK2013PhysicsDual Nature of Matter
Threshold wavelength for photoelectric emission from a metal surface is 5200Å . Photoelectrons will be emitted, when this surface is illuminated with monochromatic radiation from
Options
- A1 ~W~IR lamp
- B50 ~W~UV lamp
- C50 ~W~IR lamp
- D10 ~W~IR lamp
Correct answer
B. 50 ~W~UV lamp
Step-by-step solution
Given, ₀=5200 Å=5200 10⁻¹⁰ ~m Threshold frequency, f₀= c ₀ = 3 10⁸ 5200 10⁻¹⁰ =5.76 10¹⁴ ~Hz It lies in the frequency range of UV-rays, so 50 ~W UV lamp is used for this emission.