Questions

Nuclear sizes are expressed in a unit called "Fermi" which is a unit of length equal to 10⁻¹⁵ metre (one femtometre), used in nuclear physics. It is similar to the diameter of a proton.

Here all the given options are Exothermic reactions. Exothermic reactions are those reactions which involves the release of heat.

Generally all the combining reactions are exothermic in nature.

The point or place of origin of an earthquake is called Focus. 

And,

The point where the seismic waves reach the surface is called as Epicenter.

In the given puzzle, the logic followed is

First digits comes from the number of letters in the word

Second digit is its serial number

Third digit is the addition of first and second digits

=> SUNDAY = 6713

In India, Islamic rulers Qutb-ud-din Aibak imposed jizya on non-Muslims first time which was called kharaj-o-jizya. Jizya was abolished by the Mughal ruler Akbar in the 16th century but was re-introduced by Aurangzeb in the 17th century.