Question

large metal sheet carries an electric current along its surface. Current per unit length is $\lambda$ . Magnetic field near the metal sheet is

• A. $\frac{\lambda {\mu }_0}{2}$
• B. $\frac{\lambda {\mu }_0}{2\pi }$
• C. $\lambda {\mu }_0$
• D. $\frac{{\mu }_0}{2\lambda \pi }$

Answer 1

The correct option is A $\frac{\lambda {\mu }_0}{2}$

Ampere law in magnetism,

$\int B.dl={\mu }_{0}I$. . . .(1)

The current passing through loop is $\lambda$.

$\lambda =\frac{I}{l}$

$I=\lambda l$

From equation (1)

$2B.l={\mu }_0\lambda l$

$B=\frac{{\mu }_0\lambda }{2}$. . . . .(2)

Equation (2) gives the magnetic field near metal sheet.

The correct option is A.