Question

Given fig. shows cross-section of two long, straight
wires. The left hand wire carries current is directly
out of the page. The net magnetic field due to the
two currents is zero at point P, then which of the
following statements is correct?


(1) Current i, is directed out of the page
(2) i <i₂
(3) i >i2
(4) None of these​

Answer 1

Answer:

current i is directed out of the page

Explanation:

if so, at point p, magnetic field lines will be opposite in direction( i.e., one wil b clockwise and another wil b in anticlockwise) and equal in magnitude. hence net current will b zero.

Answer 2

Answer:

i1 >i2

Explanation:

As i1 is directed out of the page so using right hand thumb rule we get that magnetic field at point P is directed to the left side and to get the net magnetic field at point P as zero the magnetic field due to current i2 would be in opposite direction i.e in right direction. And to get the magnetic field zero i1 > i2 as i2 is nearer to point P so it should have less magnetic field then i1 which farther from point P.

Thanks