Question

The value of magnetic field due to a small element of current carrying conductor at a distance r and lying on the plane perpendicular to the element of conductor is

• A. Zero
• B. Maximum
• C. Inversely proportional to the current
• D. None of the above

Answer 1

Answer: (B)

Maximum
The Biot Savart law is used for computing the resultant magnetic field at position generated by a steady current I. According to it $B=\frac{{\mu }_{0}I}{4\pi }\int \frac{I\overrightarrow{dl}\times \overrightarrow{r}}{r^3}$.

So magnetic field at a distance r and lying on the plane perpendicular ($\pi /2$)to the element of conductor is maximum .