Modern and Nuclear Physics — 18 Physics PYQs with Answers | UKPSC PYQ Hub

Question 1

The radioactive material do not emit, which of the following?

Accepted Answer

Protons. Radioactive decay is of three types alpha, beta and gamma. Alpha is helium nucleus, Beta is electron. Thus Proton is correct answer.

Question 2

The fuel used in the fast breeder test reactor of Kalpakkam is–

Accepted Answer

Enriched uranium. Enriched uranium (Uranium-233) fuel is used in the fast breeder test reactor of Kalpakkam.

Question 3

Otto Hahn invented Atomic bomb which was based on the principle of?

Accepted Answer

Nuclear fission. Atomic bomb, invented by Otto Hawn was based on the principle of nuclear fission. In a process called nuclear fission, the nucleus of a heavy atom (such as uranium, plutonium or thorium), when bombarded with low-energy neutrons, can be split apart into lighter nuclei. When this is done, a tremendous amount of energy is released.

Question 4

The fourth dimension of Physics was introduced/pronounced by–

Accepted Answer

Einstein. Einstein introduced time as a fourth dimension of physics.

Question 5

What does term – Tachyon refers to?

Accepted Answer

Particles accelerating with speed greater than that of light. Tachyon is a hypothetical particle which moves faster than light.

Question 6

Alfred Nobel (who founded the Nobel Prize) was related to the invention of–

Accepted Answer

Dynamite. Alfred Nobel (who founded the Nobel Prize) was related to the invention of dynamite.

Question 7

Those atoms in which the number of Protons is same but the number of Neutrons are different are known as–

Accepted Answer

Isotopes. Isotopes have same number of protons and different number of Neutrons. Isobars are atoms of different chemical elements that have the same number of nucleons and Differ in atomic number but have same mass number. Isotones are two or more species of atoms or nuclei that have the same number of neutrons. Isomers are molecules or poly atomic ions with identical molecular formulae.

Question 8

Hydrogen bomb is based on _______.

Accepted Answer

Nuclear fusion. The hydrogen bomb is based on thermonuclear fusion reaction.