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

Two inductor coils of self-inductance $3\,H$ and $6\,H$ respectively are connected with a resistance $10\,\Omega$ and a battery $10\,V$ as shown in the figure. The ratio of the total energy stored at steady state in the inductors to that of the heat developed in the resistance in $10\,s$ at the steady state is (neglect mutual inductance between $L_1$ and $L_2$):-

$(a)$ $A$ closed loop is held stationary in the magnetic field between the north and south poles of two permanent magnets held fixed. Can we hope to generate current in the loop by using very strong magnets?
$(b)$ $A$ closed loop moves normal to the constant electric field between the plates of a large capacitor. Is a current induced in the loop
$\quad (i)$ when it is wholly inside the region between the capacitor plates
$\quad (ii)$ when it is partially outside the plates of the capacitor? The electric field is normal to the plane of the loop.
$(c)$ $A$ rectangular loop and a circular loop are moving out of a uniform magnetic field region to a field-free region with a constant velocity $v$. In which loop do you expect the induced emf to be constant during the passage out of the field region? The field is normal to the loops.
$(d)$ Predict the polarity of the capacitor in the situation described by the figure.

Column $I$ gives certain situations in which a straight metallic wire of resistance $R$ is used and Column $II$ gives some resulting effects. Match the statements in Column $I$ with the statements in Column $II$.

Column $I$	Column $II$
$(A)$ $A$ charged capacitor is connected to the ends of the wire	$(p)$ $A$ constant current flows through the wire
$(B)$ The wire is moved perpendicular to its length with a constant velocity in a uniform magnetic field perpendicular to the plane of motion	$(q)$ Thermal energy is generated in the wire
$(C)$ The wire is placed in a constant electric field that has a direction along the length of the wire	$(r)$ $A$ constant potential difference develops between the ends of the wire
$(D)$ $A$ battery of constant emf is connected to the ends of the wire	$(s)$ Charges of constant magnitude appear at the ends of the wire

Which of the following statements is incorrect?

$A$ conducting loop in the form of a circle is placed in a uniform magnetic field with its plane perpendicular to the direction of the field. An emf will be induced in the loop, if