Magnetic Flux

Q. A square coil ${10}^{-2}{\text{m}}^2$ area is placed with its plane perpendicular to a uniform magnetic field of intensity ${10}^3{\text{Wb/m}}^2.$ The magnetic flux through the coil is

1. $10\text{Wb}$
2. ${10}^{-5}\text{Wb}$
3. ${10}^5\text{Wb}$
4. $100\text{Wb}$

Q. The flux of a magnetic field over a closed surface is zero.

1. False
2. True

Q. A small equilateral triangular loop of side $l=1cm$ is kept inside a large circular loop of radius r such that both are coplanar and concentric. If current in the larger loop is as shown in the graph, then find the current induced in the smaller loop during the time instants given. Take anticlock wise current as positive.


List - 1 gives time instants and list - 2 gives induced current in the smaller loop. Take $\frac{{\mu }_0\pi }{2rR}=1$ where R is resistance of small loop.
$\begin{array}{cccc}& \text{List -1}& & \text{List -2}\\ \left(I\right)& 0sec& \left(p\right)& 25\mu A\\ \left(II\right)& \frac{1}{3}sec& \left(Q\right)& 12.5\mu A\\ \left(III\right)& \frac{3}{2}sec& \left(R\right)& 0\mu A\\ \left(IV\right)& \frac{5}{3}sec& \left(S\right)& -6.25\mu A\\ & & \left(T\right)& -12.5\mu A\\ & & \left(U\right)& -25\mu A\end{array}$

1. $I\to U,II\to T,III\to R,IV\to T$
2. $I\to P,II\to Q,III\to R,IV\to T$
3. $I\to U,II\to S,III\to R,IV\to T$
4. $I\to P,II\to Q,III\to T,IV\to R$

Q. The variation of magnetic susceptibility $\chi$ with absolute temperature $T$, for a ferromagnetic material, is best shown by which of the following graphs?

1. 
2. 
3. 
4.