Advertisements
Advertisements
प्रश्न
The magnetic field energy in an inductor changes from maximum to minimum value in 5.0 ms when connected to an AC source. The frequency of the source is
पर्याय
20 Hz
50 Hz
200 Hz
500 Hz
Advertisements
उत्तर
50 Hz
The magnetic field energy in an inductor is given by,
`E = 1/2 Li^2`
The magnetic energy will be maximum when the current will reach its peak value, i0, and it will be minimum when the current will become zero.
v
From the above graph of alternating current, we can see that current reduces from maximum to zero in T/4 time, where T is the time period.
So, in this case, T/4 = 5 ms
⇒ T = 20 ms
∴ Frequency , `V =1/T = 1/(20xx10^-3)=50Hz`
APPEARS IN
संबंधित प्रश्न
An inductor-coil, a capacitor and an AC source of rms voltage 24 V are connected in series. When the frequency of the source is varied, a maximum rms current of 6.0 A is observed. If this inductor coil is connected to a battery of emf 12 V and internal resistance 4.0 Ω, what will be the current?
Show that in an AC circuit containing a pure inductor, the voltage is ahead of current by π/2 in phase.
A 44 mH inductor is connected to 220 V, 50 Hz ac supply. Determine the rms value of the current in the circuit.
A coil of inductance 0.50 H and resistance 100 Ω is connected to a 240 V, 50 Hz ac supply.
(a) What is the maximum current in the coil?
(b) What is the time lag between the voltage maximum and the current maximum?
Obtain if the circuit is connected to a high-frequency supply (240 V, 10 kHz). Hence, explain the statement that at very high frequency, an inductor in a circuit nearly amounts to an open circuit. How does an inductor behave in a dc circuit after the steady state?
Obtain if the circuit is connected to a 110 V, 12 kHz supply? Hence, explain the statement that a capacitor is a conductor at very high frequencies. Compare this behaviour with that of a capacitor in a dc circuit after the steady state.
Alternating current is so called because _______.
In a circuit containing resistance only, voltage and current are ______.
Average power supplied to an inductor over one complete cycle is ______.
An inductive circuit contains resistance of 10 ohms and an inductance of 2 henry. If an A.C. voltage of 120 Volts and frequency 60 Hz is applied to this circuit, the current would be nearly ______.
Explain why the reactance offered by an inductor increases with increasing frequency of an alternating voltage.
An electrical device draws 2kW power from AC mains (voltage 223V (rms) = `sqrt(50,000)` V). The current differs (lags) in phase by `phi(tan phi = (-3)/4)` as compared to voltage. Find (i) R, (ii) XC – XL, and (iii) IM. Another device has twice the values for R, XC and XL. How are the answers affected?
What is the ratio of inductive and capacitive reactance in an ac circuit?
Draw a phasor diagram showing e and i in the case of a purely inductive circuit. A 40-turn square coil of side 0.2 m is placed in a magnetic field of induction 0.05 T with the plane of the coil perpendicular to the direction of the field. If the magnetic induction is uniformly reduced to zero in 5 milliseconds, find the emf induced in the coil.
The magnetic energy stored in an inductor of inductance 4 µH carrying a current of 2 A is ______.
In an AC circuit with a bulb and inductor, what happens to the bulb’s brightness when an iron rod is inserted into the inductor?
The magnetic potential energy stored in a certain inductor is 25 mJ, when the current in the inductor is 60 mA. This inductor is of inductance ______.
A 2 mH inductor is connected to 220 V, 50 Hz AC (X1) and then to DC (X2). Find X1 and X2.
The inductive reactance XL of a purely inductive circuit is given by ______.
A series LCR circuit is subjected to an AC signal of 200 V, 50 Hz. If the voltage across the inductor (L = 10 mH) is 31.4 V, then the current in this circuit is ______.
