Physics

Matter and Quantum Mechanics

1,448 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 physics behaviour of perfect gas and kinetic theory of gases degree of freedom: law of equipartition of energy law of equipartition of energy law of equipartition of energy and mean free path

A system consists of N particles, which have independent K relations among one another. The number of degrees of freedom of the system is given by :

  1. 3 NK

  2. N/3K

  3. 3 N/K

  4. 3N - K
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

For a system of N particles having K independent relations among them, the degrees of freedom of the system is given by 3N-K. 3N  is due to three degrees of freedom associated with each particle if all the particles are independent of each other (i.e K=0) and due to K relation among them, degrees of freedom reduces to 3N-K

Hence, Option D is correct.

Multiple choice physics behaviour of perfect gas and kinetic theory of gases degree of freedom: law of equipartition of energy law of equipartition of energy law of equipartition of energy and mean free path

The de-Broglie wavelength of a particle accelerated with $150\ volt$ potential is $10^{-10}\ m$. If it accelerated by $600\ volts$ p.d. its wavelength will be

  1. $0.25\ A^{o}$
  2. $0. 5\ A^{o}$
  3. $1.5\ A^{o}$
  4. $2\ A^{o}$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Given,

$\lambda =\dfrac{hc}{eV}\ \ \ \ where,\ V=potential$

$\lambda \ \alpha \ \dfrac{1}{V}$

${{10}^{-10}}\ \alpha \ \dfrac{1}{150}\ ......\ (1)$

$\lambda \ \alpha \ \dfrac{1}{600}\ ......\ (2)$

Divide (2) by (1)

$ \dfrac{\lambda }{{{10}^{-10}}}=\dfrac{150}{600}=\dfrac{1}{4} $

$ \Rightarrow \lambda =0.25\times {{10}^{-10}}m\ =0.25\ {{A}^{o}} $ 

Multiple choice chemistry particle nature, basic units history of atomic model atomic theory of dalton daltons atomic theory

According to Dalton's atomic theory, the smallest particle in which matter can exist is called :

  1. an atom.

  2. an ion.

  3. an electron.

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

DALTON'S ATOMIC THEORY :

1. Matter is made up of very small undivisible particle called atoms.

2. All the atoms of a given element is identical in all respect i.e. mass, shape, size, etc.

3. Atoms cannot be created nor destroyed by any chemical process.

4. Atoms of different elements are different in nature.

Multiple choice chemistry basic concepts of chemistry history of atomic model atomic theory of dalton daltons atomic theory

On which basis later researches proved that Dalton's atomic theory was not wholly correct :

  1. An atom is the ultimate

  2. Discrete particle of matter

  3. Indivisible particle of matter

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

Drawbacks of Dalton's atomic theory :


1. The atom is further subdivided into protons, neutrons, electrons.


2. The atoms of the same elements are not similar in all aspects. They may vary in mass and density. These are known as isotopes.

3. Atoms of different elements are not different in all aspects. Atoms of different elements that have the same atomic mass are called isobar.

4. According to Dalton atoms of different elements combine in simple whole-number ratio to form compounds. This is not seen in complex organic compounds.

5. This theory fails to explain the existence of allotropes.


Hence the correct option is D.

Multiple choice

Which of the following is a fundamental postulate of Quantum Mechanics?

  1. Particles can behave like waves.

  2. Energy can be transferred in discrete packets called quanta.

  3. The position and momentum of a particle cannot be simultaneously known with perfect accuracy.

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

Quantum Mechanics is based on several fundamental postulates, including the wave-particle duality of matter, the quantization of energy, and the uncertainty principle.

Multiple choice

What is the mathematical equation that describes the time evolution of a quantum system?

  1. Schrödinger's Equation

  2. Heisenberg's Uncertainty Principle

  3. Pauli Exclusion Principle

  4. Dirac Equation
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Schrödinger's Equation is a fundamental equation in Quantum Mechanics that describes the time evolution of a quantum system.

Multiple choice

Which of the following is a consequence of the wave-particle duality of matter?

  1. Electrons can behave like particles or waves, depending on the experiment.

  2. Light can exhibit both particle-like and wave-like properties.

  3. Atoms can exist in multiple energy states simultaneously.

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

The wave-particle duality of matter is a fundamental property of quantum systems, and it leads to a variety of phenomena, including the ability of particles to behave like waves and vice versa.

Multiple choice

What is the uncertainty principle?

  1. It is impossible to simultaneously know the position and momentum of a particle with perfect accuracy.

  2. It is impossible to simultaneously know the energy and time of a particle with perfect accuracy.

  3. It is impossible to simultaneously know the spin and polarization of a particle with perfect accuracy.

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

The uncertainty principle is a fundamental principle of Quantum Mechanics that states that it is impossible to simultaneously know certain pairs of physical properties, such as position and momentum, with perfect accuracy.

Multiple choice

What is the Pauli exclusion principle?

  1. No two electrons in an atom can have the same set of quantum numbers.

  2. No two protons in a nucleus can have the same set of quantum numbers.

  3. No two neutrons in a nucleus can have the same set of quantum numbers.

  4. All of the above.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The Pauli exclusion principle is a fundamental principle of Quantum Mechanics that states that no two electrons in an atom can have the same set of quantum numbers.

Multiple choice

What is the concept of quantum entanglement?

  1. When two or more particles become correlated in such a way that the state of one particle cannot be described independently of the other.

  2. When two or more particles share the same wave function.

  3. When two or more particles are linked by a common physical property.

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

Quantum entanglement is a fundamental concept in Quantum Mechanics that describes the correlation between two or more particles in such a way that the state of one particle cannot be described independently of the other.

Multiple choice

What is the concept of quantum superposition?

  1. When a particle exists in multiple states simultaneously.

  2. When a particle can be in two different locations at the same time.

  3. When a particle can have two different energies at the same time.

  4. All of the above.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Quantum superposition is a fundamental concept in Quantum Mechanics that describes the ability of a particle to exist in multiple states simultaneously.

Multiple choice

What is the concept of quantum tunneling?

  1. When a particle passes through a potential barrier even though it does not have enough energy to do so classically.

  2. When a particle disappears from one location and reappears in another without crossing the intervening space.

  3. When a particle moves faster than the speed of light.

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

Quantum tunneling is a fundamental concept in Quantum Mechanics that describes the ability of a particle to pass through a potential barrier even though it does not have enough energy to do so classically.

Multiple choice

Which of the following is the fundamental building block of matter in the Standard Model of particle physics?

  1. Electron

  2. Quark

  3. Photon

  4. Neutrino
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Quarks are the fundamental building blocks of matter in the Standard Model of particle physics. They combine to form protons, neutrons, and other hadrons.

Multiple choice

What is the force carrier of the electromagnetic interaction?

  1. Photon

  2. Gluon

  3. W and Z bosons

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

The photon is the force carrier of the electromagnetic interaction. It is a massless, chargeless particle that mediates the interactions between electrically charged particles.

Multiple choice

What is the name of the theory that describes the strong nuclear force?

  1. Quantum Chromodynamics

  2. Quantum Electrodynamics

  3. Electroweak Theory

  4. General Relativity
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Quantum Chromodynamics (QCD) is the theory that describes the strong nuclear force. It is a non-Abelian gauge theory that describes the interactions between quarks and gluons.