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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.
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उत्तर
Initial current, I1 = 5.0 A
Final current, I2 = 0.0 A
Change in current, dI = I1 − I2 = 5 A
Time taken for the change, t = 0.1 s
Average emf, e = 200 V
For self-inductance (L) of the coil, we have the relation for average emf as:
e = `"L""dl"/"dt"`
`"L" = "e"/((("dl")/("dt")))`
= `200/(5/0.1)`
= 4 H
Hence, the self-induction of the coil is 4 H.
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संबंधित प्रश्न
Explain the phenomenon of self induction
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 ?
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?
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.
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?
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?
The magnetic potential energy stored in a certain inductor is 15 mJ, when the current in the inductor is 40 mA. This inductor is of inductance ____________.
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Two coils of wire A and B are placed mutually perpendicular as shown. When current is changed in any one coil.
Magnetic flux of 12 microweber is linked with a coil. When current of 3 mA flows through it, the self inductance of the coil is ____________.
Two solenoids of same cross-sectional area have their lengths and number of turns in ratio of 1 : 2 both. The ratio of self-inductance of two solenoids is ______.
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 ______.
The self-inductance associated with a coil is independent of ______.
The self-inductance depends upon ______.
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)
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.
