Free Printable Quantization of light

Worksheets

Quantization of light

Total questions: 15

Worksheet time: 25mins

Name

Class

Date

If the frequency of incident radiation is more than threshold frequency, the process of photoelectric effect takes place _____

slowly

rapidly

gradually

instantaneously

The energy of photoelectrons emitted from a metal surface can be increased by

using light of higher frequency.

using light of longer wavelength.

using light of higher intensity.

using monochromatic, polarized light.

The photoelectric effect is when:

Electrons collide inside a metal to release photons.

One incident metal electron releases one photon.

One incident photon releases one electron from a metal.

Photons are absorbed in to metal ions releasing electrons.

The photoelectric effect only occurs if the light shining on the metal is:

coherent.

above a minimum intensity.

above a minimum frequency.

above a minimum wavelength.

Which statement about the photoelectric effect is correct?

Electrons are emitted instantaneously.

Electrons are not emitted below a certain wavelength.

You can change the energy of the electrons by changing the intensity.

Electron energy is independent of frequency.

Energy absorbed by electron is used in

A. escaping metal

B. increasing kinetic energy

C. both A and B

D. increasing frequency

A metal surface is illuminated with a beam of monochromatic electromagnetic radiation. What determines the maximum speed of the photoelectrons that are emitted from the surface?

the intensity of the radiation only

the frequency of the radiation only

the intensity and the frequency of the radiation

the frequency of the radiation and the work function of the metal

What is the maximum kinetic energy of electrons emitted from cesium (Cs), when light of frequency10¹⁵ Hz falls upon the metal? (work function for Cs is 1.8 eV)

7.728x10^-19 J

4.83 eV

1.864x10^-19 J

2.34 eV

The diagram shows a circuit involving a photoelectric cell. When UV light is shone onto the metal cathode, electrons are emitted establishing a photocurrent.
Which of the following changes could cause the photocurrent to stop?

Increasing the potential difference of the power supply.

Increasing the frequency of the UV light.

Increasing the intensity of the UV light.

Changing the metal surface to one with a smaller work function.

10.

Find the threshold wavelength for the photoelectric effect in tungsten (work function for tungsten is 4.5 eV)

138 nm

414 nm

552 nm

276 nm

11.

What is the energy of a photon of wavelength 400 nm?

2.95 eV

3.00 eV

3.09 eV

3.12 eV

12.

In photoelectric effect, electrons should be removed from the metal ______.

inner shells

surface

from core

nucleus

13.

In the formula, E_K = hf - Φ, what does 'Φ' represent?

The kinetic energy of the incident photon

The kinetic energy of the emitted electron

The threshold frquency

The work function

14.

What is the best description of 'threshold frequency'?

The minimum energy needed for electrons to escape a surface.

The maximum kinetic energy that an emitted electron has.

The minimum frequency of a photon that will cause an electron to be emitted.

The frequency that an emitted electron will have.

15.

In the formula, E_K = hf - Φ, what does 'hf' represent?

The photon energy of the incident light