Advertisements
Advertisements
Question
What are the values of the self-induced emf in the circuit of the previous problem at the times indicated therein?
Advertisements
Solution
Given:-
Self-inductance, L = 1 H
For an inductor of self-inductance L, the emf induced is given by
`e = L(di)/(dt)`
(a) At t = 100 ms,
`(di)/(dt)=0.27"A/s"`
∴ Induced emf, `e = L(di)/(dt)=1xx0.27=0.27 V`
(b) At t = 200 ms,
`(di)/(dt)=0.036"A/s"`
∴ Induced emf `= L(di)/(dt)=1xx0.036=0.036V`
(c) At t = 1 s,
`(di)/(dt)=4.1xx10^-9"A/s"`
∴ Induced emf `=L(di)/(dt)=4.1xx10^-9V`
APPEARS IN
RELATED QUESTIONS
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.
Define the coefficient 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 induced voltages ?
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?
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 pure inductors each of self-inductance L are connected in series, the net inductance is ______
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?
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 ____________.
A graph of magnetic flux `phi` versus current (I) is shown for four inductors A, B, C, D. Smaller value of self inductance is for inductor ____________.
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 ____________.
The coefficient of self inductance of a solenoid is 0.18 mH. If a core of soft iron of relative permeability 900 is inserted, then the coefficient of self inductance will become nearly ______.
What is the unit of self-inductance of a coil?
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.
Obtain an expression for the self inductance of a solenoid.
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:
