Anyone know this question?

Which force is most responsible for binding together an atom's protons and neutrons? electrostatic gravitational nuclear magnetic

The magnetic field inside a superconducting solenoid is 4.50 t. the solenoid has an inner diameter of 6.20 cm and a length of 26.0 cm. determine (a) the magnetic energy density in the field and (b) the energy stored in the magnetic field within the solenoid.

If angle "a" is 25°, angle "b" is: a) equal to angle c b) less than angle c c) greater than angle c