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

Which of the following statements is not true about matter?

  1. Particles of all forms of matter can be seen with naked eye.

  2. Particles of matter keep on dividing themselves into smaller and smaller particles.

  3. In all forms of matter, there is space among the particles.

  4. We can mix sugar in tea, coffee, etc. because of the presence of spaces among the particles of one form of matter.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Particles of matter cannot be seen with naked eye. 

Multiple choice

Directions: Which of the given options best represents the information in the reading passage? Choose the appropriate number (1 – 4).

Brownian motion involves

Directions: Answer the given question based on the following passage:

ALBERT EINSTEIN
Albert Einstein is perhaps one of the most celebrated scientists in history, especially for the 20th century. His work in physics led to an era of new discoveries and knowledge of our universe. He is however, not just known for his famous equation e= mc2, but he is also known for his contributions to other fields in science. Without Einstein, we would not have computers, be able to travel into space or have a deeper understanding of our own biology, of outer space, time and the universe.
His first major discovery was made while he was pursuing his doctorate. This discovery was the formula that could accurately describe Brownian motion which is the movement of particles in a fluid, such as liquid or gas. The idea that the motion of particles can be explained by their interaction on the molecular level has been around since ancient times. Einstein however was the first to develop an accurate mathematical model for this movement. What is fascinating is that at one point it was considered to be incorrect. Einstein, through further experimentation, proved it otherwise.
His next discovery was even more amazing and helped to build the foundation of quantum physics. This was the discovery of the quantum nature of the photoelectric effect. This phenomenon had been observed by other scientists for some time. The effect comes about when light strikes certain types of photosensitive materials. In response, these materials emit electrons. According to classical theory, it was thought that light was a wave of pure energy. If this was so, then the intensity of the light would increase the energy of the electrons being emitted. What actually happens is that increased intensity of light only increases the amount of electrons being released, but does not increase their energy. Something was not right with this model and Einstein offered an alternative. Einstein proposed that light was not just a wave of energy, but a series of particles with a specific energy. This was the proposal of light being comprised of photons and this led to his winning the Nobel Prize for science in 1921.

  1. motion of particles in a fluid

  2. quantum physics

  3. the movement of fluids

  4. the movement of gas in a liquid
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Hint: Para-2 …. Brownian motion which is the movement of particles in a fluid, such as liquid or gas.

Multiple choice

Directions: Which of the given options best represents the information in the reading passage? Choose the appropriate number (1 – 4).

Which discovery of Einstein led to the start of quantum physics?

Directions: Answer the given question based on the following passage:

ALBERT EINSTEIN
Albert Einstein is perhaps one of the most celebrated scientists in history, especially for the 20th century. His work in physics led to an era of new discoveries and knowledge of our universe. He is however, not just known for his famous equation e= mc2, but he is also known for his contributions to other fields in science. Without Einstein, we would not have computers, be able to travel into space or have a deeper understanding of our own biology, of outer space, time and the universe.
His first major discovery was made while he was pursuing his doctorate. This discovery was the formula that could accurately describe Brownian motion which is the movement of particles in a fluid, such as liquid or gas. The idea that the motion of particles can be explained by their interaction on the molecular level has been around since ancient times. Einstein however was the first to develop an accurate mathematical model for this movement. What is fascinating is that at one point it was considered to be incorrect. Einstein, through further experimentation, proved it otherwise.
His next discovery was even more amazing and helped to build the foundation of quantum physics. This was the discovery of the quantum nature of the photoelectric effect. This phenomenon had been observed by other scientists for some time. The effect comes about when light strikes certain types of photosensitive materials. In response, these materials emit electrons. According to classical theory, it was thought that light was a wave of pure energy. If this was so, then the intensity of the light would increase the energy of the electrons being emitted. What actually happens is that increased intensity of light only increases the amount of electrons being released, but does not increase their energy. Something was not right with this model and Einstein offered an alternative. Einstein proposed that light was not just a wave of energy, but a series of particles with a specific energy. This was the proposal of light being comprised of photons and this led to his winning the Nobel Prize for science in 1921.

  1. Wave nature of electric energy

  2. Light being not a form of energy

  3. Quantum nature of photoelectric effect

  4. Light being an emission of photons.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

His next discovery was even more amazing and helped to build the foundation of quantum physics. This was the discovery of the quantum nature of the photoelectric effect.

Multiple choice

Potential energy depends upon its

  1. colour

  2. motion

  3. size

  4. shape

  5. mass
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Potential energy depends upon mass because Potential energy calculated by P.E=mgh, where m is mass of the body.

Multiple choice

The zig-zag movement of the small particles suspended in the liquid or gas is called Brownian motion. Which of the following is not a conclusion provided by the Brownian motion?

a. The matter is made up of tiny particles. b. The particles of matter are constantly moving. c. The particles of matter repel each other.

  1. Only a

  2. Both a and b

  3. Only b

  4. Both b and c

  5. Only c
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

This is the correct option as this is not provided by the Brownian motion about the nature of matter.

Multiple choice

Which of the following is not a condition that will determine the physical state of matter?

a. The space between the particles. b. The kinetic energy of particles. c. The force of repulsion between the particles.

  1. Only a

  2. Both a and b

  3. Only b

  4. Both b and c

  5. Only c
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

This is the correct option as this is not a condition that will decide whether a given substance will exist as a solid, a liquid or a gas. It is the force of attraction between the particles that will decide whether a given substance will exist as a solid, a liquid or a gas

Multiple choice

Which of the following are the various states of matter? a. Solid b. Liquid c. Gas d. Plasma e. Bose Einstein condensate

  1. Only a and b

  2. Only a, b and c

  3. Only a, b, c and d

  4. All of these

  5. Only a, b, c and e
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Yes, it is the correct answer, as all  of these are  different states of matter. Apart from solid, liquid and gas plasma and BEC are also forms of matter. The plasma state consists of super energetic and super excited particles. These particles are in the form of ionised gases. The BEC is formed by cooling a gas of extremely low density, about one-hundred-thousandth the density of normal air, to super low temperatures.

Multiple choice

According to Planck, energy possessed by electrons is in pockets called

  1. Ohms

  2. Quanta.

  3. Lumens.

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

Max Planck introduced the concept of 'quanta' (singular: quantum) to explain that energy is emitted or absorbed in discrete packets, not continuously. This revolutionary idea formed the foundation of quantum mechanics. Ohms measure resistance, lumens measure luminous flux, and photons are particles of light themselves.

Multiple choice

Dalton's atomic theory describes the structure of matter. Which of the following statements is wrong about it?

  1. All matter consists of tiny particles

  2. When elements react, their atoms combine in simple, whole-number ratios.

  3. Atoms are destructible

  4. Elements are characterized by the weight of their atoms
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Atoms of an element cannot be created, destroyed and broken into smaller parts . Dalton based this hypothesis on the law of conservation of mass and on centuries of experimental evidence.

Multiple choice

Which among the following can be excluded form the drawbacks of Dalton's atomic theory of matter?

  1. It failed to explain the existence of allotropes.

  2. It failed to explain the laws of chemical combination.

  3. It failed to explain the divisibility of an atom.

  4. It failed to explain the different nature of atoms of same element .
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

According to Dalton, the atoms of same element are similar in all respects. This is wrong because atoms of some elements vary in their mass and density. Such atoms of the same element having different masses are called isotopes. For example, chlorine has two isotopes having mass numbers 35 a.m.u and 37 a.m.u..