Physics

Matter and Quantum Mechanics

1,427 Questions

This topic addresses core concepts in quantum mechanics, statistical thermodynamics, and states of matter. Questions cover quantum field theory, particle behavior, and statistical distributions. This material is essential for physics competitive exams.

Statistical ensemblesQuantum field theoryParticle physicsStates of matterWave particle duality

Matter and Quantum Mechanics Questions

Multiple choice detection and recording of x-ray images option c: imaging physics

According to photon theory of light which of the following physical quantities  associated with a photon do not / does not change as it collides with an electron is vacuum:

  1. Energy and momentum

  2. Speed and momentum

  3. Speed only

  4. Energy only
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Under the photon theory of light, a photon is a discrete bundle (or quantum) of electromagnetic (or light) energy. Photons are always in motion and, in a vacuum, have a constant speed of light to all observers, at the vacuum speed of light (more commonly just called the speed of light) of $c = 2.998 \times 10^8 m/s$

According to the photon theory of light, photons .
move at a constant velocity, $c = 2.9979 \times 10^8 m/s$ (i.e. "the speed of light"), in free space
have zero mass and rest energy.

Carry energy and momentum, which are also related to the frequency $\mu$ and wavelength $\lambda$ of the electromagnetic wave by $E = h \mu$ and $p = \dfrac{h}{\lambda}.$

Can be destroyed/created when radiation is absorbed/emitted.

Can have particle-like interactions (i.e. collisions) with electrons and other particles, such as in the Compton effect
Multiple choice detection and recording of x-ray images option c: imaging physics

Find the correct statement

  1. A free electron can absorb a photon completely.

  2. A free electron can not absorb a photon completely.

  3. A free electron can not exist.

  4. A free neutron can exist for a long time
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

According to Compton's scattering 


$\displaystyle \Delta \lambda =\dfrac{h}{mc}(1-\cos \phi )$ 

which shows a free electron can not absorb a photon completely. If a free electron absorb a photon there is nothing to share the recoil. So momentum will not conserve which is not possible.
So, the answer is option (B).

Multiple choice detection and recording of x-ray images option c: imaging physics

When X-rays or gamma rays interact with matter, there is a decrease in the energy of the X-rays or gamma rays. This is known as the ____________.

  1. photoelectric effect

  2. Raman effect

  3. Compton effect

  4. none of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Compton effect

When a light wave (Photon) is incident on an electron, there is a decrease in energy of a photon as a part of its initial energy is transferred to the electron which is scattered. This effect is called Compton effect.


Multiple choice chemistry element, compound and chemical reaction materials around us materials around us and different types of houses matter and its states

Bose-Einstein condensate state is obtained by cooling of the substance below _____.

  1. $-273^0C$
  2. $273^0C$
  3. $273K$
  4. $295K$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Bose-EInstein condensate (BEC) is the fifth state of matter which is obtained by supercooling of the substance below $-273^0C$. This state of matter is artificially prepared in a laboratory because it is difficult to obtain such a low temperature naturally.

Multiple choice nanochemistry nanotechnology applied chemistry materials chemistry

Which of the following are characteristic properties of nano particles?

  1. More surface area

  2. Quantum effects

  3. Both a and b

  4. None of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Two principal factors cause the properties of nanomaterials to differ significantly from other materials: increased relative surface area, and quantum effects. These factors can change or enhance properties such as
reactivity, strength and electrical characteristics.
Hence option C is correct.

Multiple choice physics simple machines concept of energy energy for everything forms of energy

Energy can be defined as:

  1. The capacity to do work

  2. Work done in unit time

  3. A push or a pull

  4. Attraction between two oppositely charged particles
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Energy is the capacity of a physical system to perform work. Energy exists in several forms such as heat, kinetic or mechanical energy, light, potential energy, electrical, or other forms.

Multiple choice physics physical quantities and measurement measurement of small and large distances measurement of distance unit of fundamental quantities

______________________ is/are linked through its/their definitions to the mass of the platinum-iridium cylinder stored in a vault near Paris.

  1. ampere

  2. mole

  3. candela

  4. all of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Ampere, Mole and Candela are linked through their definitions to the mass of the platinum-iridium cylinder stored in a vault near Paris.

Multiple choice physics effects of light scattering of light and its applications some natural phenomena of light natural phenomena explained by scattering

C.V Raman's major contribution was on

  1. Inelastic scattering of light by molecules

  2. Quantum statistics

  3. Theory of super conductivity

  4. Expanding universe
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Answer is A

It is also possible for the incident photons to interact with the molecules in such a way that energy is either gained or lost so that the scattered photons are shifted in frequency. Such inelastic scattering is called Raman Scattering.

Multiple choice physics scientists inventions and inventors in science indian scientist: biography and achievements scientist and their achievements

Which of the following statements is incorrect. ?

  1. Bohr gave theory of hydrogen atom and Yukawa, the theory of nuclear forces.

  2. Law of gravitation was discovered by Newton and principle of inertia by Galileo

  3. Laws of photoelectric effect were discovered by Einstein and laws of electromagnetic induction by Faraday.

  4. Neutron was discovered by J.J.Thomson and electron was discovered by James Chadwick.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Neutron was discovered by James Chadwick and electron was discovered by J.J.Thomson.

Multiple choice physics scientists inventions and inventors in science indian scientist: biography and achievements scientist and their achievements

Which of the following books is not written by Werner Heisenberg?

  1. Breakthrough

  2. The Physical Principles of the quantum theory

  3. Physics and Philosophy

  4. Physics and Beyond
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Werner Heisenberg was a german physicist and author of many theoretical looks such as :

a) The physical Principles of Quantum Theorem.
b) Physics and Philosophy
c) Physics and Beyond etc.

Multiple choice physics the essence of change forms of energy and energy conservation energy for everything forms of energy

Potential energy is classified into which two energy?

  1. Gravitational and Elastic Potential Energy

  2. Kinetic and Elastic Potential Energy

  3. Mechanical and Elastic Potential Energy

  4. None
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Gravitational and Elastic Potential Energy are two types of potential energy

Gravitational potential energy: Energy stored in the object at a certain height above ground.
Elastic potential energy:Energy stored in streched or compressed spring.