Magnetic moment & Angular momentum of the nucleus.
Nucleus consists of Proton & Neutron.
Proton:

1. Possesses angular momentum  described by the spin quantum number ; this angular momentum obeys the general rules of quantization.

Component along oz-axis
Magnitude 

2. Possesses a magnetic moment  parallel and in the same sense as its angular momentum .

Magnetic momentum of proton
 nuclear magneton
So,

Neutron: also possesses magnetic moment

But total magnetic moment of the nucleus.