Photoelectric effect NEET Level

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

• 1. 50 W Ultraviolet

• 1. 50 watt infrared lamp

• 1. 1 watt ultraviolet lamp

• 1. 1 watt infrared

If the work function for a certain metal is 3.2 x 10^-19 joule and it is illuminated with light of frequency 8 x 10¹⁴ Hz. The maximum kinetic energy of the photo-electrons would be (h= 6.63 x 10^-34 Js).

• 1. 2.1 x 10^-19 J

• 1. 8.5 x 10^-19 J

• 1. 5.3 x 10^-19 J

• 1. 3.2 x 10^-19 J

A photocell is receiving light from a source placed at a distance of 1m. If the same source is to be placed at a distance of 2 m, then the ejected electron

• 1. Moves in one-fourth energy as that of the initial energy

• 1. Moves with one-fourth momentum as that of the initial momentum

• 1. Will be half in number

• 1. Will be one-fourth in number

The minimum energy required to remove an electron is called

• 1. Stopping potential

• 1. Kinetic energy

• 1. Work function

• 1. None of these

Photoelectric effect was explained by

• 1. Einstein

• 1. Faraday

• 1. Plank

• 1. Hertz

In a photoelectric experiment for 4000 Å incident radiation, the potential difference to stop the ejection is 2 V. If the incident light is changed to 3000 Å, then the potential required to stop the ejection of electrons will be

• 1. 2 V

• 1. Less than 2 V

• 1. Zero

• 1. Greater than 2 V

Light of wavelength 4000 Å is incident on a sodium surface for which the threshold wavelength of photo-electrons is 5420 Å. The work function of sodium is

• 1. 5 eV

• 1. 3 eV

• 1. 2.29 eV

• 1. 0.57 eV

Photocell is a device to

• 1. Store photons

• 1. Measure light intensity

• 1. Convert photon energy into mechanical energy

• 1. Store electrical energy for replacing storage batteries

Photoelectrons stopping potential depends on

• 1. Frequency of incident light and nature of the cathode material

• 1. The intensity of the incident light

• 1. The frequency of the incident light

• 1. Nature of cathode material

What is the value of the maximum kinetic energy acquired by electron due to radiation of wavelength 100 nm?

• 1. 12 eV

• 1. 6.2 eV

• 1. 100 eV

• 1. 300 eV