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
Define the coefficient of self-induction.
Define self-inductance. Write its SI units.
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 ?
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-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.
Answer the following question.
When an inductor is connected to a 200 V dc voltage, a current at 1A flows through it. When the same inductor is connected to a 200 V, 50 Hz ac source, only 0.5 A current flows. Explain, why? Also, calculate the self-inductance of the inductor.
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 ____________.
A coil of self-inductance L is connected in series with a bulb B and an AC source. Brightness of the bulb decreases when ____________.
Two coils of self inductances 2 mH and 8 mH are placed so close together that the effective flux in one coil is completely linked with the other. The mutual inductance between these coils is ______.
A coil is wound on a frame of rectangular cross-section. If all the linear dimensions of the frame are increased by a factor 2 and the number of turns per unit length of the coil remains the same, self-inductance of the coil increases by a factor of ______.
What is meant by magnetic coupling coefficient?
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 ______.
A coil of self-inductance L is connected in series with a bulb and an a. c. source. Brightness of the bulb decreases when ______.
