Phys 200B – HW10
Due Tuesday 15-Feb-
10-1. Attached to the starting motor of your car
is a solenoid switch. When you turn your ignition key, current I from your battery runs through a
solenoid of length L with n turns per unit length creating a
magnetic field which acts on a steel plunger also of length L with permeability m, thereby engaging the
motor. Calculate the force on the plunger as a function of x (where x is the depth
to which the plunger is inserted into the solenoid) – Neglect fringe fields for
this calculation.
10-2 A long conducting cylinder of radius R is oriented parallel to and at a distance h from an infinite conducting plane. Determine the capacitance per unit length of the system.
10-3. Problem 5.26 in