An infinitely long wire lying along the $Y$-axis carries a current $I$ as shown in the figure. What is the magnetic flux through a circular loop of radius $R$ in the $xy$-plane? [Assume $\mu_0$ is the magnetic permeability of free space.]

The magnetic flux linked with a vector area $\overrightarrow{A}$ in a uniform magnetic field $\overrightarrow{B}$ is

Assertion $(A)$: Magnetic flux is a vector quantity.
Reason $(R)$: Value of magnetic flux can be positive, negative, or zero.

The diagram shows the magnetic field lines of a bar magnet. $A$ coil is moved from above the magnet to below it and then back to the original position. Which of the following graphs best represents the variation of magnetic flux $\Phi$ through the coil with time $t$?

$A$ long straight wire carrying a constant current $i$ is placed in the same plane as a rectangular loop of length $l$. The distance of the sides of the loop from the wire are $r_1$ and $r_2$. If the area under the curve of the magnetic field $B$ versus distance $r$ graph between $r_1$ and $r_2$ is $A$,find the magnetic flux through the loop.

The unit of magnetic flux is