Question

The threshold wavelength for photoelectric emission from a material is $5500\mathring{A}$. Photoelectrons will be emitted, when this material is illuminated with monochromatic radiation from a
A. $75W$ infra-red lamp
B. $10W$ infra-red lamp
C. $75W$ ultra-violet lamp
D. $10W$ ultra-violet lamp
Choose the correct answer from the options given below:

• A. C only
• B. B and Conly
• C. C and D only
• D. A and D only

Answer 1

Answer: (C)

$\lambda <5500\mathring{A}$ for photoelectric emission
${\lambda }_{uv}<5500\mathring{A}$