A solenoid has length 120 cm and diameter 40 cm A toroid has

A solenoid has length 120 cm and diameter 4.0 cm. A toroid has a square cross section. 4.0 cm on a side, and an inner radius of 16 cm. Both have 4(H) turns, and each carries a current of 2.5 A. (a) Determine the magnitude of the magnetic field inside the solenoid. (b) Determine the magnitude of the magnetic field inside the toroid at the inner radius. (c) Determine the magnitude of the magnetic field inside the toroid at the outer radius.

Solution

a)

Magnetic field due to a solenoid is given by

B=u_oNI/L =(4pi*10^-7)*400*2.5/1.2

B=1.047*10^-3 T or 1.047 mT

b)

Magnetic field inside the toriod at the inner radius r=16 cm is

B=u_oNI/2pir =(4pi*10^-7)*400*2.5/2pi*0.16

B=1.25*10^-3 T or 1.25 mT

c)

Magnetic field inside the toriod at the outer radius r=16 cm is

B=(4pi*10^-7)*400*2.5/2pi*0.2

B=1*10^-3 T or 1mT