Question1
A stable nucleus is composed of Z protons and N neutrons. Is the mass of nucleus identical to the sum of the masses of the constituent particles? If not, which is bigger? Write down an expression for the mass of the nucleus mnuc, in terms of the proton mass mp, neutron mass mn and any additional terms.
Question2
Three long, parallel, straight wires pass throughout the vertices of an equilateral triangle that has sides L = 11.6 cm. A dot indicates that the direction of the current is out of the screen and a cross indicates that the direction of the current is into the screen. Each current is 14.0 A.
(a) Find out the magnetic field at the location of the upper wire due to the currents in two lower wires.
(b) Find out the force per unit length on the upper wire.