Physics: Dual Nature of Radiation and Matter Class 12 MCQ

1. Who proposed the concept of wave-particle duality?

a) Albert Einstein
b) Max Planck
c) Louis de Broglie
d) Niels Bohr

Answer:

c) Louis de Broglie

Explanation:

Louis de Broglie proposed the concept that particles can exhibit wave-like characteristics and vice versa.

2. The photoelectric effect demonstrates the ______ nature of light.

a) Wave
b) Particle
c) Oscillatory
d) Periodic

Answer:

b) Particle

Explanation:

The photoelectric effect, where light dislodges electrons from a surface, showcases the particle nature of light, implying photons.

3. Which of the following has the shortest wavelength?

a) Ultraviolet light
b) Infrared light
c) Microwaves
d) Radio waves

Answer:

a) Ultraviolet light

Explanation:

Ultraviolet light has a shorter wavelength than infrared light, microwaves, and radio waves.

4. The threshold frequency is the frequency:

a) Above which photoelectric emission starts
b) Below which photoelectric emission stops
c) At which maximum emission occurs
d) At which minimum emission occurs

Answer:

a) Above which photoelectric emission starts

Explanation:

The threshold frequency is the minimum frequency required to initiate the photoelectric effect.

5. De Broglie wavelength is associated with:

a) Only particles
b) Only waves
c) Both particles and waves
d) Neither particles nor waves

Answer:

c) Both particles and waves

Explanation:

De Broglie introduced the idea that all matter (particles) has a wave-like nature, thereby associating a wavelength with particles.

6. The work function of a metal is:

a) The maximum kinetic energy of emitted electrons
b) The minimum energy required to remove an electron from the metal
c) The energy of the incident photon
d) The energy of the emitted photon

Answer:

b) The minimum energy required to remove an electron from the metal

Explanation:

The work function is the minimum energy necessary to dislodge an electron from the surface of a metal.

7. Electrons exhibit wave-like properties when they:

a) Revolve around the nucleus
b) Are at rest
c) Move through a potential difference
d) Pass through a slit

Answer:

d) Pass through a slit

Explanation:

When electrons pass through a slit, they exhibit interference patterns, demonstrating their wave-like properties.

8. The stopping potential in the photoelectric effect is used to determine:

a) The threshold frequency
b) The maximum kinetic energy of emitted electrons
c) The energy of incident photons
d) The work function

Answer:

b) The maximum kinetic energy of emitted electrons

Explanation:

The stopping potential gives the negative potential that stops the most energetic photoelectrons, thereby determining their maximum kinetic energy.

9. The phenomenon where electron waves are diffracted by a crystal lattice is called:

a) Electron diffraction
b) X-ray diffraction
c) Electron interference
d) X-ray interference

Answer:

a) Electron diffraction

Explanation:

When electron waves interact with a crystal lattice and get diffracted, it's termed electron diffraction.

10. The photoelectric effect could not be explained by:

a) Quantum theory
b) Wave theory of light
c) Particle theory of light
d) Electromagnetic theory

Answer:

b) Wave theory of light

Explanation:

The wave theory of light couldn't account for certain observations in the photoelectric effect, leading to the development of the quantum theory.

11. The Compton effect is related to the scattering of:

a) Protons
b) Electrons
c) Neutrons
d) Photons

Answer:

d) Photons

Explanation:

The Compton effect describes the scattering of photons (X-rays) by electrons in a material.

12. The dual nature of electrons was confirmed by:

a) Photoelectric effect
b) Compton scattering
c) Electron diffraction
d) X-ray diffraction

Answer:

c) Electron diffraction

Explanation:

The interference patterns observed in electron diffraction experiments confirm the wave-like nature of electrons.

13. Which effect confirmed the particle nature of light?

a) Interference
b) Diffraction
c) Polarization
d) Photoelectric effect

Answer:

d) Photoelectric effect

Explanation:

The photoelectric effect, where light is absorbed by matter and ejects electrons, confirmed the particle nature of light.

14. For the photoelectric effect to occur, the incident light should have a frequency:

a) Equal to threshold frequency
b) Less than threshold frequency
c) Greater than threshold frequency
d) Unrelated to the threshold frequency

Answer:

c) Greater than threshold frequency

Explanation:

For the photoelectric effect, the incident light's frequency must surpass the metal's threshold frequency.

15. Wave nature of matter is not observable for:

a) Electrons
b) Protons
c) Baseballs
d) Photons

Answer:

c) Baseballs

Explanation:

The wave nature of matter is significant only for microscopic particles, like electrons or protons. For macroscopic objects, like baseballs, it's negligible.

Leave a Comment

Your email address will not be published. Required fields are marked *

Scroll to Top