# Quantum Theory MCQs with Answers

Which principle states that the exact position and momentum of a particle cannot both be precisely determined simultaneously?

a) Heisenberg’s uncertainty principle

b) Schrödinger’s equation

c) Planck’s principle

d) Bohr’s model

**Answer: ** a) Heisenberg’s uncertainty principle

Which of the following is a fundamental property of a quantum particle?

a) Mass

b) Charge

c) Spin

d) All of the above

**Answer: ** d) All of the above

The wave-particle duality of light was first proposed by:

a) Max Planck

b) Albert Einstein

c) Louis de Broglie

d) Erwin Schrödinger

**Answer: ** c) Louis de Broglie

The mathematical equation that describes the behavior of quantum particles is known as:

a) Heisenberg’s equation

b) Schrödinger’s equation

c) Planck’s equation

d) Einstein’s equation

**Answer: ** b) Schrödinger’s equation

The discrete energy levels of an atom are explained by:

a) Bohr’s model

b) Schrödinger’s equation

c) Planck’s principle

d) Heisenberg’s uncertainty principle

**Answer: ** a) Bohr’s model

Which of the following particles is NOT a fermion?

a) Electron

b) Proton

c) Neutron

d) Photon

**Answer: ** d) Photon

The process of a quantum particle passing through a potential barrier that it classically cannot overcome is called:

a) Quantum tunneling

b) Quantum entanglement

c) Quantum superposition

d) Quantum scattering

**Answer: ** a) Quantum tunneling

The property of a quantum system that allows two particles to be instantaneously connected regardless of the distance between them is called:

a) Quantum tunneling

b) Quantum entanglement

c) Quantum superposition

d) Quantum scattering

**Answer: ** b) Quantum entanglement

The principle that states that the total probability of all possible outcomes of a quantum measurement must equal 1 is known as:

a) Conservation of probability

b) Conservation of energy

c) Conservation of momentum

d) Conservation of mass

**Answer: ** a) Conservation of probability

The smallest indivisible unit of electromagnetic radiation is called:

a) An electron

b) A proton

c) A photon

d) A neutron

**Answer: ** c) A photon

The quantized energy levels of a bound particle in a box are called:

a) Orbitals

b) Eigenstates

c) Wavefunctions

d) Harmonic oscillators

**Answer: ** b) Eigenstates

The principle that states that no two identical fermions can occupy the same quantum state simultaneously is known as:

a) The Pauli exclusion principle

b) The Aufbau principle

c) The Hund’s rule

d) The Bohr’s principle

**Answer: ** a) The Pauli exclusion principle

Which of the following phenomena is explained by the wave-particle duality of quantum particles?

a) Interference

b) Diffraction

c) Polarization

d) All of the above

**Answer: ** d) All of the above

The concept in quantum mechanics that describes the simultaneous existence of multiple states or positions of a particle is called:

a) Superposition

b) Entanglement

c) Tunneling

d) Reflection

**Answer: ** a) Superposition

The property of a quantum system that allows it to be in multiple states or positions at the same time is known as:

a) Superposition

b) Entanglement

c) Tunneling

d) Reflection

**Answer: ** a) Superposition

The concept in quantum mechanics that describes the correlation between the properties of entangled particles, regardless of the distance between them, is called:

a) Superposition

b) Entanglement

c) Tunneling

d) Reflection

**Answer: ** b) Entanglement

The process in which a quantum particle “jumps” discontinuously from one energy level to another is called:

a) Quantum tunneling

b) Quantum entanglement

c) Quantum superposition

d) Quantum leap

**Answer: ** d) Quantum leap

The concept in quantum mechanics that describes the behavior of particles as waves and waves as particles is called:

a) Wave-particle duality

b) Superposition

c) Entanglement

d) Tunneling

**Answer: ** a) Wave-particle duality

The branch of quantum mechanics that deals with the statistical behavior of large ensembles of quantum particles is called:

a) Quantum electrodynamics

b) Quantum chromodynamics

c) Quantum field theory

d) Quantum statistical mechanics

**Answer: ** d) Quantum statistical mechanics

The concept in quantum mechanics that describes the behavior of particles as waves and waves as particles is known as:

a) Wave-particle duality

b) Superposition

c) Entanglement

d) Tunneling

**Answer: ** a) Wave-particle duality

The concept in quantum mechanics that describes the uncertainty in the position and momentum of a particle is known as:

a) Heisenberg’s uncertainty principle

b) Schrödinger’s equation

c) Planck’s principle

d) Bohr’s model

**Answer: ** a) Heisenberg’s uncertainty principle

The phenomenon in which a particle passes through a barrier that classically it should not be able to pass through is called:

a) Quantum tunneling

b) Quantum entanglement

c) Quantum superposition

d) Quantum scattering

**Answer: ** a) Quantum tunneling

The concept in quantum mechanics that describes the instantaneous connection between entangled particles, regardless of the distance between them, is called:

a) Quantum tunneling

b) Quantum entanglement

c) Quantum superposition

d) Quantum scattering

**Answer: ** b) Quantum entanglement

The mathematical equation that describes the behavior of quantum particles is known as:

a) Heisenberg’s equation

b) Schrödinger’s equation

c) Planck’s equation

d) Einstein’s equation

**Answer: ** b) Schrödinger’s equation

Which of the following statements is true about quantum mechanics?

a) It is a theory that describes the behavior of macroscopic objects.

b) It is a deterministic theory that can precisely predict the outcome of any measurement.

c) It is a probabilistic theory that provides statistical predictions for the behavior of microscopic particles.

d) It is a classical theory that is based on Newtonian mechanics.

**Answer: ** c) It is a probabilistic theory that provides statistical predictions for the behavior of microscopic particles.

The concept in quantum mechanics that describes the simultaneous existence of multiple states or positions of a particle is called:

a) Superposition

b) Entanglement

c) Tunneling

d) Reflection

**Answer: ** a) Superposition

The principle that states that the total probability of all possible outcomes of a quantum measurement must equal 1 is known as:

a) Conservation of probability

b) Conservation of energy

c) Conservation of momentum

d) Conservation of mass

**Answer: ** a) Conservation of probability

The smallest indivisible unit of electromagnetic radiation is called:

a) An electron

b) A proton

c) A photon

d) A neutron

**Answer: ** c) A photon

The quantized energy levels of a bound particle in a box are called:

a) Orbitals

b) Eigenstates

c) Wavefunctions

d) Harmonic oscillators

**Answer: ** b) Eigenstates

Which of the following particles is NOT a fermion?

a) Electron

b) Proton

c) Neutron

d) Photon

**Answer: ** d) Photon

The concept in quantum mechanics that describes the correlation between the properties of entangled particles, regardless of the distance between them, is called:

a) Superposition

b) Entanglement

c) Tunneling

d) Reflection

**Answer: ** b) Entanglement

The process in which a quantum particle “jumps” discontinuously from one energy level to another is called:

a) Quantum tunneling

b) Quantum entanglement

c) Quantum superposition

d) Quantum leap

**Answer: ** d) Quantum leap

The principle that states that no two identical fermions can occupy the same quantum state simultaneously is known as:

a) The Pauli exclusion principle

b) The Aufbau principle

c) The Hund’s rule

d) The Bohr’s principle

**Answer: ** a) The Pauli exclusion principle

The branch of quantum mechanics that deals with the statistical behavior of large ensembles of quantum particles is called:

a) Quantum electrodynamics

b) Quantum chromodynamics

c) Quantum field theory

d) Quantum statistical mechanics

**Answer: ** d) Quantum statistical mechanics

The concept in quantum mechanics that describes the behavior of particles as waves and waves as particles is known as:

a) Wave-particle duality

b) Superposition

c) Entanglement

d) Tunneling

**Answer: ** a) Wave-particle duality

Which of the following phenomena is explained by the wave-particle duality of quantum particles?

a) Interference

b) Diffraction

c) Polarization

d) All of the above

**Answer: ** d) All of the above

The concept in quantum mechanics that describes the behavior of particles as waves and waves as particles is called:

a) Wave-particle duality

b) Superposition

c) Entanglement

d) Tunneling

**Answer: ** a) Wave-particle duality

The principle that states that the exact position and momentum of a particle cannot both be precisely determined simultaneously is known as:

a) Heisenberg’s uncertainty principle

b) Schrödinger’s equation

c) Planck’s principle

d) Bohr’s model

**Answer: ** a) Heisenberg’s uncertainty principle

The phenomenon in which a particle passes through a barrier that classically it should not be able to pass through is called:

a) Quantum tunneling

b) Quantum entanglement

c) Quantum superposition

d) Quantum scattering

**Answer: ** a) Quantum tunneling

The concept in quantum mechanics that describes the instantaneous connection between entangled particles, regardless of the distance between them, is called:

a) Quantum tunneling

b) Quantum entanglement

c) Quantum superposition

d) Quantum scattering

**Answer: ** b) Quantum entanglement

The principle that states that the total probability of all possible outcomes of a quantum measurement must equal 1 is known as:

a) Conservation of probability

b) Conservation of energy

c) Conservation of momentum

d) Conservation of mass

**Answer: ** a) Conservation of probability

The smallest indivisible unit of electromagnetic radiation is called:

a) An electron

b) A proton

c) A photon

d) A neutron

**Answer: ** c) A photon

The quantized energy levels of a bound particle in a box are called:

a) Orbitals

b) Eigenstates

c) Wavefunctions

d) Harmonic oscillators

**Answer: ** b) Eigenstates

Which of the following particles is NOT a fermion?

a) Electron

b) Proton

c) Neutron

d) Photon

**Answer: ** d) Photon

The concept in quantum mechanics that describes the correlation between the properties of entangled particles, regardless of the distance between them, is called:

a) Superposition

b) Entanglement

c) Tunneling

d) Reflection

**Answer: ** b) Entanglement

The process in which a quantum particle “jumps” discontinuously from one energy level to another is called:

a) Quantum tunneling

b) Quantum entanglement

c) Quantum superposition

d) Quantum leap

**Answer: ** d) Quantum leap

The principle that states that no two identical fermions can occupy the same quantum state simultaneously is known as:

a) The Pauli exclusion principle

b) The Aufbau principle

c) The Hund’s rule

d) The Bohr’s principle

**Answer: ** a) The Pauli exclusion principle

The branch of quantum mechanics that deals with the statistical behavior of large ensembles of quantum particles is called:

a) Quantum electrodynamics

b) Quantum chromodynamics

c) Quantum field theory

d) Quantum statistical mechanics

**Answer: ** d) Quantum statistical mechanics

The concept in quantum mechanics that describes the behavior of particles as waves and waves as particles is known as:

a) Wave-particle duality

b) Superposition

c) Entanglement

d) Tunneling

**Answer: ** a) Wave-particle duality

Which of the following phenomena is explained by the wave-particle duality of quantum particles?

a) Interference

b) Diffraction

c) Polarization

d) All of the above

**Answer: ** d) All of the above

The concept in quantum mechanics that describes the behavior of particles as waves and waves as particles is called:

a) Wave-particle duality

b) Superposition

c) Entanglement

d) Tunneling

**Answer: ** a) Wave-particle duality

The principle that states that the exact position and momentum of a particle cannot both be precisely determined simultaneously is known as:

a) Heisenberg’s uncertainty principle

b) Schrödinger’s equation

c) Planck’s principle

d) Bohr’s model

**Answer: ** a) Heisenberg’s uncertainty principle

The phenomenon in which a particle passes through a barrier that classically it should not be able to pass through is called:

a) Quantum tunneling

b) Quantum entanglement

c) Quantum superposition

d) Quantum scattering

**Answer: ** a) Quantum tunneling

The concept in quantum mechanics that describes the instantaneous connection between entangled particles, regardless of the distance between them, is called:

a) Quantum tunneling

b) Quantum entanglement

c) Quantum superposition

d) Quantum scattering

**Answer: ** b) Quantum entanglement

a) Conservation of probability

b) Conservation of energy

c) Conservation of momentum

d) Conservation of mass

**Answer: ** a) Conservation of probability

a) An electron

b) A proton

c) A photon

d) A neutron

**Answer: ** c) A photon

a) Orbitals

b) Eigenstates

c) Wavefunctions

d) Harmonic oscillators

**Answer: ** b) Eigenstates

a) Electron

b) Proton

c) Neutron

d) Photon

**Answer: ** d) Photon

a) Superposition

b) Entanglement

c) Tunneling

d) Reflection

**Answer: ** b) Entanglement

a) Quantum tunneling

b) Quantum entanglement

c) Quantum superposition

d) Quantum leap

**Answer: ** d) Quantum leap

a) The Pauli exclusion principle

b) The Aufbau principle

c) The Hund’s rule

d) The Bohr’s principle

**Answer: ** a) The Pauli exclusion principle

a) Quantum electrodynamics

b) Quantum chromodynamics

c) Quantum field theory

d) Quantum statistical mechanics

**Answer: ** d) Quantum statistical mechanics

a) Wave-particle duality

b) Superposition

c) Entanglement

d) Tunneling

**Answer: ** a) Wave-particle duality

a) Interference

b) Diffraction

c) Polarization

d) All of the above

**Answer: ** d) All of the above

a) Wave-particle duality

b) Superposition

c) Entanglement

d) Tunneling

**Answer: ** a) Wave-particle duality

The principle that states that the exact position and momentum of a particle cannot both be precisely determined simultaneously is known as:

a) Heisenberg’s uncertainty principle

b) Schrödinger’s equation

c) Planck’s principle

d) Bohr’s model

**Answer: ** a) Heisenberg’s uncertainty principle

a) Quantum tunneling

b) Quantum entanglement

c) Quantum superposition

d) Quantum scattering

**Answer: ** a) Quantum tunneling

a) Quantum tunneling

b) Quantum entanglement

c) Quantum superposition

d) Quantum scattering

**Answer: ** b) Quantum entanglement

a) Conservation of probability

b) Conservation of energy

c) Conservation of momentum

d) Conservation of mass

**Answer: ** a) Conservation of probability

a) An electron

b) A proton

c) A photon

d) A neutron

**Answer: ** c) A photon