Discuss the types of $AC$ generator. How much power they deliver? What is the frequency of $AC$ generator?

Write down the names of two devices which work on the principle of electromagnetic induction.

$A$ semicircle conducting ring of radius $R$ is placed in the $xy$ plane,as shown in the figure. $A$ uniform magnetic field is set up along the $x$-axis. No $emf$ will be induced in the ring if:

$A$ conducting loop in the shape of a right-angled isosceles triangle of height $10 \ cm$ is kept such that the $90^{\circ}$ vertex is very close to an infinitely long conducting wire (see the figure). The wire is electrically insulated from the loop. The hypotenuse of the triangle is parallel to the wire. The current in the triangular loop is in counterclockwise direction and increases at a constant rate of $10 \ As^{-1}$. Which of the following statement$(s)$ is(are) true?
$(A)$ The magnitude of induced emf in the wire is $\left(\frac{\mu_0}{\pi}\right) \ V$
$(B)$ If the loop is rotated at a constant angular speed about the wire,an additional emf of $\left(\frac{\mu_0}{\pi}\right) \ V$ is induced in the wire
$(C)$ The induced current in the wire is in the opposite direction to the current along the hypotenuse
$(D)$ There is a repulsive force between the wire and the loop

In the circuit shown below,all the inductors (assumed ideal) and resistors are identical. The current through the resistance on the right is $I$ after the key $K$ has been switched $ON$ for a long time. The currents through the three resistors (in order,from left to right) immediately after the key is switched $OFF$ are

$A$ wire loop is placed in a region of time-varying magnetic field which is oriented orthogonally to the plane of the loop as shown in the figure. The graph shows the magnetic field variation as a function of time. Assume the positive $emf$ is the one which drives a current in the clockwise direction as seen by the observer in the direction of $B$. Which of the following graphs best represents the induced $emf$ as a function of time?