Question

A solenoid of $1200$ tums is wound uniformly in a single layer on a glass tube $2\, m$ long and $02\, m$ in diameter The magnetic intensity at the center of the solenoid when a current of $2 A$ flows through it is:

• A. $2.4 \times 10^3 A m ^{-1}$
• B. $1.2 \times 10^3 A m ^{-1}$
• C. $1 Am ^{-1}$
• D. $2.4 \times 10^{-3} A m ^{-1}$

Answer 1

Answer: (B)

$1.2 \times 10^3 A m ^{-1}$

Answer 2

Magnetic field at centre inside the solenoid is given by
B=μ0​nI
So magnetic intensity at centre
H=μ0​B​=nI=(21200​)(2)
H=1.2×103Am−1