The mass of the proton is $1840$ times that of the electron. If the potential difference applied is $V$,the kinetic energy of the proton is ............ $KeV$.

What is a cathode ray discharge tube? Write down its uses.

According to $J.J. Thomson$,the deflection of cathode particles in an electric discharge tube by electric and magnetic fields depends on which factors?

Neutrons are found in atoms of all elements except in

Positronium is the name given to an atom-like combination formed between

The nucleus of an atom can be assumed to be spherical. The radius of the nucleus of mass number $A$ is given by $1.25 \times 10^{-13} \times A^{1/3} \ cm$. The radius of the atom is $1 \ \mathring{A}$. If the mass number is $64$,then the fraction of the atomic volume that is occupied by the nucleus is: