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 physics electric fields introduction to electrostatic force electric force charging and discharging

What does coulomb's law of attraction and repulsion states?

  1. F is directly proportional to $q _1q _2$ and inversely proportional to $(r _{12})^2$
  2. F is directly proportional to $q _1q _2$ and inversely proportional to $(r _{12})$
  3. F is indirectly proportional to $q _1q _2$ and directly proportional to $(r _{12})^2$

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

The Coulomb law is the force between two charges $q _1$ and $q _2$ when the separation between them is $r _{12}$. 

Here , $F=\dfrac{kq _1q _2}{r _{12}^2}$
Thus, F is proportional to $q _1q _2$ and invewrsely proportional to $r _{12}^2$.

Multiple choice luminous intensity measurements physics

In the interference pattern, energy is

  1. created at the position of maxima

  2. destroyed at the positions of minima

  3. conserved but is redistributed

  4. not conserved
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

conserved but is redistributed

Multiple choice social science universe and space the big bang and the early development of the universe origin of universe evolution of the universe

What is the name of the hypothetical theory that would unify all the fundamental forces of nature?

  1. Grand unified theory

  2. Unified field theory

  3. Classical field theory

  4. Super grand unified theory
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

A theory that would unify all four fundamental forces (gravity, electromagnetism, strong nuclear, and weak nuclear) is often referred to as a Theory of Everything or, in some contexts, a Super Grand Unified Theory.

Multiple choice physics semiconductors band theory of solids, a brief introduction electron energies in solids energy bands

What is an energy gap?

  1. the space between two orbital shells
  2. the energy equal to the energy acquired by an electron passing a $1 V$ electric field

  3. the energy band in which electrons can move freely

  4. an energy level at which an electron can exist
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
  1. Orbiting electrons contains energy and are confirmed to definite energy levels.
    2. The various shells in an atom represent these levels.
    3. Therefore, to move an electron from the lower shell to a higher shell a certain amount of energy is required.
    3. Below the conduction band is the forbidden band or energy gap, electrons are never found in this band, but may travel back and forth through it, provided they do not come to rest in the band.
    4. As the electrons can also lose energy as well as receive it when an electron loses energy it moves to a lower shell.
    5. And supplying more energy than is needed will only cause the electron to move to the next higher shell.
    6. It means that an energy gap is the spacing between two orbital shells.
Multiple choice physics measurements and units some examples of derived units fundamental and derived quantities fundamental and derived units

Density is a ________ physical quantity.

  1. fundamental

  2. derived

  3. semi-derived

  4. semi-fundamental
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Density is calculated from mass and volume by the relation   $\rho = \dfrac{m}{V}$
Since, density depends on other fundamental quantity for its measurement.
So, density is a derived physical quantity.
Multiple choice evs look, learn and experience matter: states, classification and properties study of matter general introduction: importance and scope of chemistry

Classification of matter helps us to:

  1. study things systematically

  2. share information with others

  3. know the properties of all the members of a group if we know about one

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

Classification of matter helps us to:


(i) Know the properties of all members of a group if we know about one.


(ii) Study things systematically.

(iii) Share information with others.


Option D is correct.

Multiple choice

Which of the following is NOT true about electromagnetic (EM) waves?

  1. they were discovered by James Clerk Maxwell

  2. they can travel through the vacuum of space

  3. they can only travel through solids and gases

  4. their fields run perpendicular to each other
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Electromagnetic waves do not require a medium; they can travel through the vacuum of space. Therefore, the statement that they can only travel through solids and gases is false.

Multiple choice chemistry quantitative chemistry avogadro hypothesis avogadro's law avogadro law

Which statement is linked with the idea that two identical containers filled with different gases will contain the same number of particles?

  1. Mosely

  2. Avagadro

  3. Dalton

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

Avagadro stated that when two identical containers are filled with different gases at same pressure and temperature, they contain same number of particles.

So, the statement is linked with Avagadro.

Multiple choice physics quantum physics photons concept of photon photons and photoelectric effect

Which one of the following branch of physics deals the impossibility of making simultaneous, arbitrarily precise measurements of the momentum and the position of an electron.

  1. thermodynamics

  2. quantum mechanics

  3. classical electrodynamics

  4. special relativity

  5. general relativity
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Heisenberg's Uncertainty Principle, as a part of quantum mechanics, theorizes that the position and momentum of an electron cannot be measured precisely at the same time, that is, there is a minimum associated natural error in measurement of the two simultaneously. 

The error in measurement of the two is quantified as $\Delta x.\Delta p\geq\dfrac{\hbar}{2}$

Multiple choice chemistry substances in the surroundings - their states and properties measurement of density properties of substances fundamental and derived units

Which of the following statements are true for density?

  1. It is a physical property of matter

  2. It is a scalar quantity

  3. It is the mass per unit volume of a substance

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

Density is a physical property of a substance and is defined as the mass per unit volume of a substance. The density of a body is the amount of mass contained per unit volume of the body.

Since it does not have any direction it is a scalar quantity.