1
JEE Main 2021 (Online) 25th July Morning Shift
Numerical
+4
-1
A circular conducting coil of radius 1 m is being heated by the change of magnetic field $$\overrightarrow B$$ passing perpendicular to the plane in which the coil is laid. The resistance of the coil is 2 $$\mu$$$$\Omega$$. The magnetic field is slowly switched off such that its magnitude changes in time as

$$B = {4 \over \pi } \times {10^{ - 3}}T\left( {1 - {t \over {100}}} \right)$$

The energy dissipated by the coil before the magnetic field is switched off completely is E = ___________ mJ.
2
JEE Main 2021 (Online) 25th February Morning Shift
Numerical
+4
-1
A coil of inductance 2 H having negligible resistance is connected to a source of supply whose voltage is given by V = 3t volt. (where t is in second). If the voltage is applied when t = 0, then the energy stored in the coil after 4 s is _______J.
3
JEE Main 2020 (Online) 6th September Morning Slot
Numerical
+4
-0
A part of a complete circuit is shown in the figure. At some instant, the value of current I is 1A and it is decreasing at a rate
of 102 A s–1. The value of the potential difference VP – VQ , (in volts) at that instant, is _________.

4
JEE Main 2020 (Online) 5th September Morning Slot
Numerical
+4
-0
Two concentric circular coils, C1 and C2 are
placed in the XY plane. C1 has 500 turns, and
of 20 cm. C2 carries a time dependent current
I(t) = (5t2 – 2t + 3) A where t is in s. The emf
induced in C1 (in mV), at the instant t = 1 s is
$${4 \over x}$$. The value of x is ___ .