Advertisements
Advertisements
प्रश्न
A coil of self-inductance 3 H carries a steady current of 2 A. What is the energy stored in the magnetic field of the coil?
Advertisements
उत्तर
Energy stored in the magnetic field, UB = `1/2 "LI"^2 = 1/2 xx 3 xx 2^2 = 6` J
APPEARS IN
संबंधित प्रश्न
Current in a circuit falls from 5.0 A to 0.0 A in 0.1 s. If an average emf of 200 V induced, give an estimate of the self-inductance of the circuit.
Define self-inductance. Write its SI units.
A toroidal solenoid with air core has an average radius of 15 cm, area of cross-section 12 cm2 and has 1200 turns. Calculate the self-inductance of the toroid. Assume the field to be uniform across the cross-section of the toroid.
The currents flowing in the two coils of self-inductance L1 = 16 mH and L2 = 12 mH are increasing at the same rate. If the power supplied to the two coil is equal, find the ratio of induced voltages ?
The currents flowing in the two coils of self-inductance L1 = 16 mH and L2 = 12 mH are increasing at the same rate. If the power supplied to the two coil is equal, find the ratio of the energies stored in the two coils at a given instant ?
Define self-inductance of a coil. Show that magnetic energy required to build up the current I in a coil of self inductance L is given by `1/2 LI^2`
Derive the expression for the self-inductance of a long solenoid of cross sectional area A and length l, having n turns per unit length.
A plot of magnetic flux (Φ) versus current (I) is shown in the figure for two inductors A and Β. Which of the two has larger value of self inductance?

Define self inductance. Write its S.I. units.
Derive an expression for self inductance of a long solenoid of length l, cross-sectional area A having N number of turns.
A constant current i is maintained in a solenoid. Which of the following quantities will increase if an iron rod is inserted in the solenoid along its axis?
(a) magnetic field at the centre
(b) magnetic flux linked with the solenoid
(c) self-inductance of the solenoid
(d) rate of Joule heating.
Two solenoids have identical geometrical construction but one is made of thick wire and the other of thin wire. Which of the following quantities are different for the two solenoids?
(a) self-inductance
(b) rate of Joule heating if the same current goes through them
(c) magnetic field energy if the same current goes through them
(d) time constant if one solenoid is connected to one battery and the other is connected to another battery.
A magnetic flux of 8 × 10−4 weber is linked with each turn of a 200-turn coil when there is an electric current of 4 A in it. Calculate the self-inductance of the coil.
An inductor of inductance 5.0 H, having a negligible resistance, is connected in series with a 100 Ω resistor and a battery of emf 2.0 V. Find the potential difference across the resistor 20 ms after the circuit is switched on.
Define self-inductance.
Obtain an expression for the self-inductance of a solenoid.
The coefficient of self-inductance of a solenoid is 0.20 mH. If a core of soft iron of relative permeability 900 is inserted, then the coefficient of self-inductance will become nearly ______
An e.m.f. of 10 volt is produced by a self inductance when the current changes at a steady rate from 6 A to 4 A in 1 millisecond. The value of self inductance is ____________.
Two coils of wire A and B are placed mutually perpendicular as shown. When current is changed in any one coil.

A coil of self-inductance L is connected in series with a bulb B and an AC source. Brightness of the bulb decreases when ____________.
A graph of magnetic flux `(phi)` versus current (I) is shown for four inductors A, B, C and D. Larger value of self-inductance is for inductor ____________.

An inductor may store energy in
What is the unit of self-inductance of a coil?
A coil of wire of a certain radius has 600 turns and a self-inductance is 108 mH. The self-inductance of a second similar coil of 500 turns will be:
The self-inductance depends upon ______.
The self inductance L of a solenoid of length l and area of cross-section A, with a fixed number of turns N increases as ______.
The inductance of a solenoid L having diameter d. Let n be the number of turns per unit length. The inductance per unit length near the middle of a solenoid is ______.
(Assume that, l = current passes through the turns, µ0 = Permeability of vacuum)
Calculate the self-inductance of a coil using the following data obtained when an AC source of frequency `(200/pi)` Hz and a DC source are applied across the coil.
| AC Source | ||
| S.No. | V (volts) | I (A) |
| 1 | 3.0 | 0.5 |
| 2 | 6.0 | 1.0 |
| 3 | 9.0 | 1.5 |
| DC Source | ||
| S.No. | V (volts) | I (A) |
| 1 | 4.0 | 1.0 |
| 2 | 6.0 | 1.5 |
| 3 | 8.0 | 2.0 |
A current of 1A flows through a coil when it is connected across a DC battery of 100V. If the DC battery is replaced by an AC source of 100 V and angular frequency of 100 rad s-1, the current reduces to 0.5 A. Find
- the impedance of the circuit.
- self-inductance of coil.
- Phase difference between the voltage and the current.
An air-cored solenoid, 40 cm long and of cross-sectional area 5 cm2, is tightly wound with 400 turns of copper wire and carries a steady current of 10 A. (a) Calculate the self-inductance of the solenoid. (b) Find the emf induced if the current in the solenoid decreases to zero in 0.2 s.
State the factors on which the magnetic coupling coefficient of two coils depends.
Obtain an expression for the self inductance of a solenoid.
The current in a coil changes from 50A to 10A in 0.1 second. The self inductance of the coil is 20H. The induced e.m.f. in the coil is ______.
The current flowing through an inductor of self-inductance L is continuously increasing at constant rate. The variation of induced e.m.f. (e) verses dI/dt is shown graphically by figure

The current flowing through an inductor of self inductance ‘L’ is continuously increasing at constant rate. The variation of induced e.m.f. (e) versus `((dI)/(dt))`is shown graphically by:
What property of a coil is called self-inductance?
Which ratio defines the self-inductance of a coil using magnetic flux linkage?
What does \[I\] represent, and what is its SI unit?
What is the dimensional formula of self-inductance?
Which set of quantities describes the long solenoid used to derive its self-inductance?
For an air (or vacuum) core, which permeability is used in the solenoid derivation?
How does a magnetic core of relative permeability \[\mu_r\] change the solenoid self-inductance expression?
Where is the EMF induced in self-inductance, as compared with mutual inductance?
What is the SI unit of both self-inductance and mutual inductance?
Which applications are associated with self-inductance and mutual inductance, respectively?




