filter
  • Subject:

    ...

  • Topic:

    ...

The threshold wavelength for photoelectric emission from a material is 5200 Å. Photo-electrons will be emitted when this material is illuminated with monochromatic radiation from a 

(a) 50 watt infrared lamp

(b) 50 watt ultraviolet lamp

(c) 1 watt ultraviolet lamp

(d) Both (b) and (c)