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प्रश्न
Explain why the inductance of two coils connected in parallel is less than the inductance of either coil.
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उत्तर १
- For a parallel combination of two coils, the current through each parallel inductor is a fraction of the total current and the voltage across each parallel inductor is the same.
- As a result, a change in total current will result in less voltage dropped across the parallel array than for any one of the individual inductors.
- There will be less voltage drop across parallel inductors for a given rate of change in current than for any of the individual inductors.
- Less voltage for the same rate of change in current results in less inductance.
- Thus, the total inductance of two coils is less than the inductance of either coil.
उत्तर २
When two inductors with inductances L1 and L2 are connected in parallel, the equivalent inductance is given by
`1/"L"_"equivalent" = 1/"L"_1 + 1/"L"_2`
which is less than the individual inductance value L1 and L2.
As a result, the inductance of two parallel coils is smaller than the inductance of either coil.
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संबंधित प्रश्न
Explain the phenomenon of self induction
In a given coil of self-inductance of 5 mH, current changes from 4 A to 1 A in 30 ms. Calculate the emf induced in the coil.
Write the SI unit and dimention of of co-efficient of self induction
Define self-inductance. Write its SI units.
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.
Consider the self-inductance per unit length of a solenoid at its centre and that near its ends. Which of the two is greater?
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.
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An inductor-coil carries a steady-state current of 2.0 A when connected across an ideal battery of emf 4.0 V. If its inductance is 1.0 H, find the time constant of the circuit.
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.
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Choose the correct option
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Obtain an expression for the self-inductance of a solenoid.
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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 ______
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Energy needed to establish an alternating current I in a coil of self-inductance L is
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The self-inductance depends upon ______.
Consider an infinitely long wire carrying a current I(t), with `(dI)/(dt) = λ` = constant. Find the current produced in the rectangular loop of wire ABCD if its resistance is R (Figure).

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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 |
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.
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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

