Q.

A solenoid of 1200 turns is wound uniformly in a single layer on a glass tube 2 m long and 0.2 m in diameter. The magnetic intensity at the center of the solenoid when a current of 2 A flows through it is                   [2023]

1 2.4×103 Am-1  
2 1.2×103 Am-1  
3 1 Am-1  
4 2.4×10-3 Am-1  

Ans.

(2)

B=μ0ni=μ0Nli

                 =4π×10-7×12002×2=48π×10-5 T

H=Bμ0=48π×10-54π×10-7=12×102=1.2×103 A/m