Nuclear Physics MCQ Quiz - Objective Question with Answer for Nuclear Physics - Download Free PDF

Calculation:
The nuclear fusion, fission, and β decay convert some matter into energy.

Nuclear fusion is generally possible for nuclei with low atomic number and nuclear fission for nuclei with high atomic number.

The β decay proceeds by weak forces.

Ans: A → (p, q), B → (p, r), C → (p, s), D → (p, q, r)

Calculation:
Beta (β) particles are electrons emitted by the nucleus whenever a neutron is converted into a proton. Gamma rays are electromagnetic radiations. An alpha particle is a doubly ionized helium atom. The rest mass of a neutron is slightly greater than the rest mass of a proton.

Ans: A

Calculation:
The mass number of the products are m1 = 216 and m2 = 4. Let K1 and K2 be the kinetic energies of the two particles.

From energy conservation:

Q = 5.5 MeV = K1 + K2     (1)

From conservation of linear momentum:

√(2 × m1 × K1) = √(2 × m2 × K2)     (2)

Eliminate K1 using equations (1) and (2) and substitute the values of m1 and m2 to get:

K2 = 5.4 MeV

Calculation:
In beta-decay, a neutron in the nucleus decays as:

10n → 11p + 0−1e

Calculation:

 Beta rays are the electrons emitted by the nucleus when a neutron is converted to a proton.

Reaction: 10n → 11p + 0−1e

Ans: C

The correct answer is Kudankulam.

• Kudankulam Nuclear Power Plant is the largest nuclear power station in India by capacity.

Key Points

• Kudankulam Nuclear Power Plant is located 650 km south of Chennai, in the Tirunelveli district of Tamilnadu, India.
• The power plant will have a combined capacity of 6000 Mega Watt upon completion.
• The Atomic Energy Commission was established in 1948 by the efforts of Dr. Homi Jahangir Bhabha, the father of Atomic Energy Research in India.
• India's first atomic research reactor 'Apsara' started working in Trombay (near Mumbai) but India's first Nuclear Power reactor was established at Tarapur in 1969.
• Production of nuclear energy requires uranium, thorium, and heavy water, Uranium is found in Jharkhand, Rajasthan, and Meghalaya.

The correct answer is Stable.

CONCEPT:

• Radioactivity: Radioactive decay is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is considered radioactive.
  • A radioactive nucleus consists of an unstable assembly of protons and neutrons which becomes more stable by emitting an alpha, a beta particle, or a gamma photon.
  • Atoms are radioactive if their nuclei are unstable and spontaneously (and random) emit various particles α, β, and/or γ radiations.
• Isotopes: The atoms of an element having the same atomic number but a different mass number are called isotopes. All isotopes have the same chemical properties.
• Isobars: The nuclei which have the same mass number (A) but a different atomic number (Z) are called isobars. 

EXPLANATION:

U₉₂²³⁸ -----→ A46119 + B46119

• Since the U -238 is an unstable atomic nucleus. The nucleus having an even number of protons and neutrons then that nucleus will be stable.
• After splitting into two identical parts it produced two stable nuclei because both have an even number of protons and neutrons. Hence option 2 is correct. 

CONCEPT: 

• Radioactivity: 
  • Radioactive decay is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is considered radioactive.
  • A radioactive nucleus consists of an unstable assembly of protons and neutrons which becomes more stable by emitting an alpha, a beta particle, or a gamma photon.
  • Atoms are radioactive if their nuclei are unstable and spontaneously (and random) emit various particles α, β, and/or γ radiations.
• Three crucial forms of Radioactivity:
  • Gamma Decay-(Photons having high energy are throw down).
  • Beta Decay-(Discharge consists of Electrons).
  • Alpha Decay-(Discharge consists of a Helium nucleus). 
• The following table shows the list of particles with their respective features. 

EXPLANATION:

• From above it is clear that the that an alpha particle consist of two proton and two neutrons and they are tightly bound.
• An alpha-particle is identical to the nucleus of a helium atom. Therefore option 1 is correct.

The correct answer is Fossils.

CONCEPT:

Radiocarbon dating: 

• It also called carbon-14 method was developed by the American physicist Willard F. Libby in about 1946 and has proved to be a versatile technique of dating fossils and archaeological specimens from 500 to 50,000 years old.
• The method is widely used by Pleistocene geologists, anthropologists, archaeologists, and investigators in related fields.
• Radiocarbon dating or Carbon-14 dating method.

​Important Points

​EXPLANATION:

• Carbon-14 dating is a method of age determination that depends upon the decay to nitrogen of radiocarbon (carbon-14 isotope).
• Carbon-14 is continually formed in nature by the interaction of neutrons with nitrogen-14 in the Earth’s atmosphere; the neutrons required for this reaction are produced by cosmic rays interacting with the atmosphere.
• Radiocarbon present in molecules of atmospheric carbon dioxide enters the biological carbon cycle: It is absorbed from the air by green plants and then passed on to animals through the food chain.
• Radiocarbon decays slowly in a living organism, and the amount lost is continually replenished as long as the organism takes in air or food and once the organism dies, however, it ceases to absorb carbon-14, so that the amount of the radiocarbon in its tissues steadily decreases.
• Carbon-14 has a half-life of 5,730 ± 40 years i.e., half the amount of the radioisotope present at any given time will undergo spontaneous disintegration during the succeeding 5,730 years.
• Because carbon-14 decays at this constant rate, an estimate of the date at which an organism died can be made by measuring the amount of its residual radiocarbon.

The correct answer is isotones.

CONCEPT:

• The nuclei have been classified based on the number of protons (atomic number) or the total number of nucleons (mass number) as follows:

EXPLANATION:

• From the above, it is clear that nuclei having the same number of neutrons but a different mass number are called isotones. Therefore option 3 is correct.

CONCEPT:

NEUTRONS:

• In 1932, J. Chadwick discovered another subatomic particle which had no charge and a mass nearly equal to that of a proton. It was eventually named as a neutron.
• Neutrons are present in the nucleus of all atoms, except hydrogen.
• In general, a neutron is represented as ‘n’.
• The mass of a neutron is 1.6750 x 10^-27 kg.
• The mass of an atom is therefore given by the sum of the masses of protons and neutrons present in the nucleus.

EXPLANATION:

• Neutrons and protons are found in the nucleus of an atom.
• Neutrons were discovered by James Chadwick. Therefore option 1 is correct.

Additional Information

The correct answer is Higgs boson.

Key Points

• God Particle spotted on 4-7-2012 is also called Higgs boson.
• Higgs boson is an elementary particle in the Standard Model of particle physics.
• It is produced by the quantum excitation of the Higgs field.
• Higgs's idea was that the universe is bathed in an invisible field similar to a magnetic field. Every particle feels this field—now known as the Higgs field.

Important Points

• Noble prize in 2013 in physics had been given in the field of Universe.
• Two scientists had won the Nobel prize in physics for their work on the theory of the Higgs boson.
• Peter Higgs, from the UK, and Francois Englert from Belgium, had shared the prize.
• In the 1960s, they were among several physicists who proposed a mechanism to explain why the most basic building blocks of the Universe have mass.
• The mechanism predicts a particle - the Higgs boson - which was finally discovered in 2012 at the Large Hadron Collider (LHC) at Cern, in Switzerland.

Concept: 

• Radioactivity: 
  • Radioactive decay is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is considered radioactive.
  • A radioactive nucleus consists of an unstable assembly of protons and neutrons which becomes more stable by emitting an alpha, a beta particle, or a gamma photon.
  • Atoms are radioactive if their nuclei are unstable and spontaneously (and random) emit various particles α, β, and/or γ radiations.
• Three crucial forms of Radioactivity:
  • Gamma Decay- (Photons having high energy are throw down).
  • Beta Decay- (Discharge consists of Electrons).
  • Alpha Decay- (Discharge consists of a Helium nucleus). 
• The following table shows the list of particles with their respective features.

Explanation:

• Charge of proton = +e
• From above it is clear that the charge on an alpha particle is +2e.
• That represents the α particles are 2 times the charge of proton

The correct answer is Strong nuclear force.

Key Points

• Strong nuclear forces are responsible for holding the nuclei of atoms together. This is the most dominant force in reactions and is so strong that it binds protons with similar charges with the nucleus.
• It is the most attractive in nature but can be repulsive sometimes. It has a very short range of just 1fm.

Additional Information

• Fundamental forces or interactions are those forces of nature as without them all things will fall apart.
• There are four fundamental forces of nature. These are as follows:

1. Gravitational Force
2. Electromagnetic Force
3. Weak Nuclear Force
4. Strong Nuclear Force

CONCEPT:

• The Atomic mass is the sum of protons and neutrons.

• In the nucleus of an atom, there are protons and neutrons.

Number of protons = Atomic number of an element.

Nuclei = neutron + proton

EXPLANATION:

Given that: mass number = 23 and atomic number = 11.

Number of protons = Atomic number = 11

IMPORTANT POINTS:

• Sodium is a chemical element with Atomic number 11 and Symbol Na.
• Mass number = Number of protons + Number of neutrons, hence the number of neutrons is 12.

• Isotopes are elements having different numbers of neutrons and the same number of protons.