Question

In the figure shown a semi-circular wire loop is placed in uniform field of $1T.$ The plane of the loop is perpendicular to the field. The magnetic force on the loop is :

• A. $2N$
• B. $4N$
• C. $8N$
• D. $Zero$

Answer 1

Answer: (C)

$8N$

for circular path effective length$=2r$
$=2$
$F=$ F due to semi circular wire + F due to straight wire
$=Bi{l}_1+Bi{l}_2$
$=1\times 2\times 2\times 1+1\times 2\times 2$
$=8N$