Question

5) A solenoid comprises 500,000 turns of wire and is 10 cm long and 1.0 cm in radius.
a) Find the resultant magnetic field inside the coil if a current of 1 μA flows through the wire.
b) How would this change if the core is filled with mumetal (μ = 300 μ0 ).

6) The solenoid of Q5 is placed in a region where the perpendicular magnetic field strength is varying sinusoidally by 20 μT at a rate of 50 Hz.
Find the resultant emf induced in the coil.​​​​​​​

5) A solenoid comprises 500,000 turns of wire and is 10 cm long and 1.0 cm in radius a) Find the resultant magnetic field inside the coil if a current of 1 μΑ flows through the wire. b) How would this change if the core is filled with mumetal (μ-300 μο). 6) The solenoid of Q5 is placed in a region where the perpendicular magnetic field strength is varying sinusoidally by 20 at a rate of 50 Hz. Find the resultant emf induced in the coil.

Answer 1

Total turns, N = 500,000 length of solenoid, l = 1cm = 1 times 10^-2 m turns per unit length, n = N/l n = 500000/1 times 10^-2 n = 5 times 10^7 (a) I = 1 mu = 1 times 10^-6 A magnetic field inside the solenoid B = mu_0 n I = 4 pi times 10^-7 times (5 times 10^7) times 1 times 10^-6 = 6.283 times 10^-5 wb/m^2 or T (b) if mu = 300 mu_0 B = mu n I = 300 mu_0 n I = 300 times 6.283 times 10^-5 = 0.0188 = 0.019T