Question

please help me solve this

Answer 1

The answer will be 3

Answer 2

length of wire = no of turns × circumference

20 = 9×2×pi×R
R=20/2×pi×9

for 2

R`=20/2×pi×3

magnetic field at the centre of the circular loop is given by

$\frac{x}{y} = \frac{ \frac{ui \times 9\pi}{2 \times 10} }{ \frac{ui \times 3\pi}{2 \times 10} } \\ \: substitution \: \: answer = \frac{9}{3} = \frac{3}{1}$
(3) option