$A$ loop $ABCDEFA$ of straight edges has six corner points $A(0,0,0), B(5,0,0), C(5,5,0), D(0,5,0), E(0,5,5)$ and $F(0,0,5)$. The magnetic field in this region is $\overrightarrow{B}=(3 \hat{i}+4 \hat{k}) \; T$. The quantity of magnetic flux through the loop $ABCDEFA$ (in $\text{Wb}$) is:

The unit of magnetic flux is

$A$ circular disc of radius $0.2 \; m$ is placed in a uniform magnetic field of induction $\frac{1}{\pi} \; Wb/m^2$ in such a way that its axis makes an angle of $60^{\circ}$ with $\vec{B}$. The magnetic flux linked with the disc is..... $Wb$.

Imagine rolling a sheet of paper into a cylinder and placing a bar magnet near its end as shown in the figure. What can you say about the sign of $\vec B \cdot d\vec A$ for every area element $d\vec A$ on the surface of the cylinder?

Explain the concept of magnetic flux.

Given below are two statements $:$ one is labelled as Assertion $(A)$ and the other is labelled as Reason $(R)$.
Assertion $(A) :$ Magnetic monopoles do not exist.
Reason $(R) :$ Magnetic field lines are continuous and form closed loops.
In the light of the above statements, choose the most appropriate answer from the options given below.