Q. A circular loop of radius 0.0157 m carries a current of 2.0 A. The magnetic field at the center of the loop is $\lbrack\mu_{0} = 4\pi \times 10^{- 7}Wb - A^{- 1}m^{- 1}\rbrack$
A) $1.57 \times 10^{- 5}Wb - m^{2}$
B) $8.0 \times 10^{- 5}\ Wb - m^{2}$
C) 2.0 $\times 10^{- 5}\ Wb - m^{2}$
D) 3.14 $\times 10^{- 5}\ Wb - m^{2}$
Explanation
(b) $r = 0.0157\ m,I = 2$A
$B = \frac{\mu_{0}I}{2r}$
$= \frac{4\pi \times 10^{- 7} \times 2}{2 \times 0.0157} = 8 \times 10^{- 5}Wbm^{- 2}Wbm^{- 2}.$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.