Question

In the figure, shown the magnetic induction at O due to the whole length of the conductor is

• A. $\frac { \mu _ { 0 } i } { r }$
• B. $\frac { \mu _ { 0 } i } { 2 r }$
• C. $\frac { \mu _ { 0 } i } { 4 r }$
• D. Zero

Answer 1

Answer: (C)

$\frac { \mu _ { 0 } i } { 4 r }$

Answer 2

The induction due to $A B$ and $C D$will be zero. Hence the whole induction will be due to the semicircular part $B C$.