a. A current I was passed through a rectangular plate a×b (a ≪ b). Modulus
of longitudinal elasticity of plate E. Determine how much the size of a will
decrease under the influence of magnetic forces.
b. Soft copper” flows ” at a pressure of 4 ⋅ 107 Pa, and steel-at a pressure of
5 ⋅ 108 Pa. Estimate the minimum magnetic field induction that will cause
copper and steel to ”flow”.