Advertisements
Advertisements
प्रश्न
An average emf of 20 V is induced in an inductor when the current in it is changed from 2.5 A in one direction to the same value in the opposite direction in 0.1 s. Find the self-inductance of the inductor.
Advertisements
उत्तर
Let the self-inductance of the inductor be L.
Average emf induced in the inductor, V = 20 V
Change in current, di = i2 − i1 = 2.5 − (−2.5) = 5 A
Time taken for the change, dt = 0.1 s
The voltage induced in the inductor is given by
\[V = L\frac{di}{dt}\]
\[ \Rightarrow 20 = L\left( \frac{5}{0 . 1} \right)\]
\[ \Rightarrow 20 = L \times 50\]
\[ \Rightarrow L = \frac{20}{50} = \frac{4}{10} = 0 . 4 H\]
APPEARS IN
संबंधित प्रश्न
Explain the phenomenon of self induction
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.
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.
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.
A coil having inductance 2.0 H and resistance 20 Ω is connected to a battery of emf 4.0 V. Find (a) the current at the instant 0.20 s after the connection is made and (b) the magnetic field energy at this instant.
Consider a small cube of volume 1 mm3 at the centre of a circular loop of radius 10 cm carrying a current of 4 A. Find the magnetic energy stored inside the cube.
Choose the correct option
A current through a coil of self-inductance 10 mH increases from 0 to 1 A in 0.1 s. What is the induced emf in the coil?
Explain why the inductance of two coils connected in parallel is less than the inductance of either coil.
Two pure inductors each of self-inductance L are connected in series, the net inductance is ______
Obtain an expression for the self-inductance of a solenoid.
When a coil is connected to a D.C. source of e.m.f. 12 volt, then a current of 4 ampere flows in it. If the same coil is connected to a 12 volt, 25 cycle/s A.C sources, then the current flowing in it is 2.4 A. The self-inductance of the coil will be ______
When current i passes through an inductor of self-inductance L, energy stored in it is 1/2. L i2. This is stored in the ______.
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 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)
State the factors on which the magnetic coupling coefficient of two coils depends.
A toroid of a circular cross-section of radius 0.05 m has 2000 windings and a self-inductance of 0.04 H. What is (a) the current through the windings when the energy in its magnetic field is 2 × 10−6 J and (b) the central radius of the toroid?
A coil of self-inductance L is connected in series with a bulb and an a. c. source. Brightness of the bulb decreases when ______.
In a coil, the current changes form −2 A to +2 A in 0.2 s and induces an emf of 0.1 V. The selfinductance of the coil is ______.
