Question

Consider a circular coil of wire, carrying current $I$, forming a magnetic dipole. The magnetic flux through an infinite plane that contains the circular coil and excluding the circular coil area is given by ${\phi }_i$ The magnetic flux through the area of the circular coil area is given by ${\phi }_0$.

• A. ${\phi }_i=-{\phi }_0$
• B. ${\phi }_i>{\phi }_0$
• C. ${\phi }_i<{\phi }_0$
• D. ${\phi }_i={\phi }_0$

Answer 1

The correct option is A

${\phi }_i=-{\phi }_0$

Step 1. Given Data,

A circular coil of wire, carrying current $I$, forming a magnetic dipole.

The magnetic flux through an infinite plane that contains the circular coil and excluding the circular coil area is given by ${\phi }_i$.

The magnetic flux through the area of the circular coil area is given by ${\phi }_0$.

We have to choose which of the following option is correct.

Step 2. Explantion of correct options,

1. Magnetic field line of ring will form close loops.
2. Magnetic field lines going inside are equal to the magnetic field lines coming out.
3. Therefore, ${\phi }_i=-{\phi }_0$.

Hence, the correct option is$\text{'}A\text{'}$.