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
विकल्प
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 inductance of 2.0 H, a capacitance of 18μF and a resistance of 10 kΩ is connected to an AC source of 20 V with adjustable frequency.
(a) What frequency should be chosen to maximize the current in the circuit?
(b) What is the value of this maximum current?
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.
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?
Alternating current is so called because _______.
An inductor of inductance L, a capacitor of capacitance C and a resistor of resistance ‘R’ are connected in series to an ac source of potential difference ‘V’ volts as shown in the figure.
The potential difference across L, C, and R is 40 V, 10 V and 40 V, respectively. The amplitude of the current flowing through the LCR series circuit is `10sqrt2 "A"`. The impedance of the circuit is:
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?
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.
What alternating voltage is applied across the pure inductor of inductance \[L\]?
Which equation results from applying Kirchhoff's Voltage Law to the pure inductor?
What differential equation follows when \[v=v_m\sin\omega t\] is applied across a pure inductor?
With \[C=0\], which expression gives the current before conversion to sine form?
What is the current amplitude \[i_m\] for a pure inductor?
Which expression defines inductive reactance in terms of angular frequency and inductance?
What is the inductive reactance of a pure inductor with \[L=25.0\,\mathrm{mH}\] at \[f=50\,\mathrm{Hz}\]?
How do transformer cores operate to enable efficient transfer of electrical energy between coils?
What do inductors in inductive filters block while allowing low-frequency or DC components to pass?
