SSC JE Electrical Engineering 22 Jan 2018 Evening Paper

Question : 127 of 200

Marks: +1, -0

Determine the value of magnetic field (in mT) at the center of a 20 cm long solenoid, if the solenoid has 200 turns and carrying a current of 4 A.

Solution:

Given data
l = 20 cm = 0.2 m
N = 200
I = 4A.
Magnetic field (B)

= µ_o µ_r H

Now,

H={NI}/\l={200×4}/0.2

= 4000 AT/m

⇒B=µ_0µ_rH

=4π×10^{-7}×4000

∴ B = 5 mT

Go to Question:

Prev Question

Next Question