Question

Three infinitely long wires each carrying a current 1 A are placed such that one end of each wire is at origin and one of these wires are along x-axis, y-axis and z-axis. Magnetic induction at point P (–2,0,0) is –

• A.
• B.
• C. $\frac { \mu _ { 0 } } { 8 \pi } ( - \hat { \mathrm { j } } + \hat { \mathrm { k } } )$
• D.

Answer 1

Answer: (C)

$\frac { \mu _ { 0 } } { 8 \pi } ( - \hat { \mathrm { j } } + \hat { \mathrm { k } } )$

Answer 2

No magnetic field at P due to wire in x-axis

(due to wire in y-axis) =

(due to wire in z-axis) = $\frac { \mu _ { 0 } \mathrm { I } } { 4 \pi \mathrm { a } } - \hat { \mathrm { j } }$

\ = = $\frac { \mu _ { 0 } \mathrm { I } } { 8 \pi } ( - \hat { \mathrm { j } } + \hat { \mathrm { k } } )$ =