A wire carrying current I and other carrying 2I in the same direction – McqOptions

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1.	A wire carrying current I and other carrying 2I in the same direction produces a magnetic field B at the mid point. What will be the field when 2I wire is switched off [AFMC 2005]
A.	B / 2
B.	2B
C.	B
D.	4B
Answer» D. 4B

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