Question
Question: Two parallel wires carrying current I and 2I in the same direction, have magnetic field B at the mid...
Two parallel wires carrying current I and 2I in the same direction, have magnetic field B at the midpoint between them. If current 2I is switched off then magnetic field at the midpoint will be-
A
B
B
B/2
C
4B
D
B4
Answer
B
Explanation
Solution
B = 
–
= 
when 2I is switched off
B¢ = 
= 
= B 