$\beta$ decay

photoelectric effect

pair production

none of the above

has positive electric charge with equal magnitude to that of an electron.

has no net electric charge.

has negative electric charge.

orbiting the nucleus.

Columbic Force

Gravitational Force

Centripetal Force

Nuclear force.

loss of energy

stopping power of absorbing medium

range of medium

none of the above 

In this process electron- proton pair is produced

In this process, positron will be attracted towards an electron and they both disappear

this is one of the mode of $\beta$ decay

none of the above

used to find the decay constants of various radioactive elements

giving energy - life time relationship

giving energy - decay constant relationship

all the above

 $N_7^{14}$  

 $B_7^{12}$  

 $N_7^{13}$  

none of above

positive He ion

 $\alpha$ particle

a proton

a negative He ion