HARD
JEE Main
IMPORTANT
Earn 100

A closed circuit consists of a source of constant emf ξ and a choke coil of inductance L, connected in series. The active resistance of the whole circuit is equal to R. At the moment t=0, the choke coil inductance was decreased abruptly, η times. Find the current in the circuit as a function of time t.

Instruction: During a stepwise change of inductance, the total magnetic flux (flux linkage) remains constant.

Important Questions on ELECTRODYNAMICS

HARD
JEE Main
IMPORTANT
Problems in General Physics>Chapter 3 - ELECTRODYNAMICS>ELECTROMAGNETIC INDUCTION. MAXWELL'S EQUATIONS>Q 3.327.

Find the time dependence of the current flowing through the inductance L, of the circuit shown in the figure, after the switch Sw is shorted at the moment t=0.

Question Image

HARD
JEE Main
IMPORTANT
Problems in General Physics>Chapter 3 - ELECTRODYNAMICS>ELECTROMAGNETIC INDUCTION. MAXWELL'S EQUATIONS>Q 3.328.

In the circuit shown in the figure, an emf ξ, a resistance R and coil inductance L1 and L2, are known. The internal resistance of the source and the coil resistances are negligible. Find the steady state currents in the coils, after the switch Sw was shorted.

Question Image

HARD
JEE Main
IMPORTANT
Problems in General Physics>Chapter 3 - ELECTRODYNAMICS>ELECTROMAGNETIC INDUCTION. MAXWELL'S EQUATIONS>Q 3.329.
Calculate the mutual inductance of a long straight wire and a rectangular frame with sides a and b. The frame and the wire lie in the same plane, with the side b being closest to the wire, separated by a distance I from it, and oriented parallel to it.
HARD
JEE Main
IMPORTANT
Problems in General Physics>Chapter 3 - ELECTRODYNAMICS>ELECTROMAGNETIC INDUCTION. MAXWELL'S EQUATIONS>Q 3.330.
Determine the mutual inductance of a doughnut coil and an infinite straight wire passing along its axis. The coil has a rectangular cross-section, it's inside radius is equal to a, and the outside one, to b. The length of the doughnut's cross-sectional side, parallel to the wire, is equal to h. The coil has N turns. The system is located in a uniform magnetic field with permeability μ.
HARD
JEE Main
IMPORTANT
Problems in General Physics>Chapter 3 - ELECTRODYNAMICS>ELECTROMAGNETIC INDUCTION. MAXWELL'S EQUATIONS>Q 3.331.
Two thin concentric wires shaped as circles with radii a and b lie in the same plane. Allowing for a≪b, find,
(a) their mutual inductance,
(b) the magnetic flux through the surface enclosed by the outside wire, when the inside wire carries a current I.
HARD
JEE Main
IMPORTANT
Problems in General Physics>Chapter 3 - ELECTRODYNAMICS>ELECTROMAGNETIC INDUCTION. MAXWELL'S EQUATIONS>Q 3.334.
There are two stationary loops with mutual inductance L12. The current in one of the loops starts to be varied as I1=αt, where α is a constant, t is time. Find the time dependence I2(t) of the current in the other loop, whose inductance is L2 and resistance is R.
HARD
JEE Main
IMPORTANT
Problems in General Physics>Chapter 3 - ELECTRODYNAMICS>ELECTROMAGNETIC INDUCTION. MAXWELL'S EQUATIONS>Q 3.335.

A coil of inductance L=2.0 μH and resistance R=1.0 Ω, is connected to a source of constant emf ξ=3.0 V. A resistance R0=2.0 Ω, is connected in parallel with the coil. Find the amount of heat generated in the coil, after the switch Sw is disconnected. The internal resistance of the source is negligible.

Question Image

HARD
JEE Main
IMPORTANT
Problems in General Physics>Chapter 3 - ELECTRODYNAMICS>MOTION OF CHARGED PARTICLES IN ELECTRIC AND MAGNETIC FIELDS>Q 3.372.
At the moment t=0, an electron leaves one plate of a parallel-plate capacitor, with a negligible velocity. An accelerating voltage, varying as V=at, where a=100 V s-1, is applied between the plates. The separation between the plates is l=5.0 cm. What is the velocity of the electron at the moment it reaches the opposite plate?