question_answer

Two thin metallic strips, carrying current in the direction shown, cross each other perpendicularly without touching but being close to each other, as shown in the figure. The regions which contain some points of zero magnetic induction are:

A)  \[I\] and \[II\]                                  

B)  \[I\] and \[III\]

C)  \[I\] and \[IV\]                

D)  \[II\] and\[III\]

Correct Answer: C

Solution :

Magnetic Held due to both currents at each point on line \[CD\] being equal and opposite cancel while at each point on line \[AB\] they are added up. Hence, magnetic induction in regions I and IV will be zero.