$A$ flux of $1 \ mWb$ passes through a strip having an area $A = 0.02 \ m^2$. The plane of the strip is at an angle of $60^{\circ}$ to the direction of a uniform field $B$. The value of $B$ is

$A$ coil of $100$ turns and area $5 \text{ cm}^2$ is placed in a magnetic field $B = 0.2 \text{ T}$. The normal to the plane of the coil makes an angle of $60^o$ with the direction of the magnetic field. The magnetic flux linked with the coil is:

$A$ 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:

$(a)$ Magnetic field lines show the direction (at every point) along which a small magnetised needle aligns (at the point). Do the magnetic field lines also represent the lines of force on a moving charged particle at every point?
$(b)$ Magnetic field lines can be entirely confined within the core of a toroid,but not within a straight solenoid. Why?
$(c)$ If magnetic monopoles existed,how would the Gauss's law of magnetism be modified?
$(d)$ Does a bar magnet exert a torque on itself due to its own field? Does one element of a current-carrying wire exert a force on another element of the same wire?
$(e)$ Magnetic field arises due to charges in motion. Can a system have magnetic moments even though its net charge is zero?

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.]

If the magnetic flux is expressed in $Weber$,then magnetic induction can be expressed in