Advertisements
Advertisements
प्रश्न
When an AC source is connected to an ideal inductor show that the average power supplied by the source over a complete cycle is zero.
उत्तर
The average power supplied by the source over a complete cycle is given as
P = VIcosϕ
where cosϕ is called the power factor.
For pure inductive circuit, the phase difference between current and voltage is `pi/2`
`=>cosphi=cos""pi/2=0`
Therefore, the average power dissipated is zero.
APPEARS IN
संबंधित प्रश्न
Prove theoretically the relation between e.m.f. induced in a coil and rate of change of magnetic flux in electromagnetic induction.
Transformers are used ______.
The current in a discharging LR circuit is given by i = i0 e−t/τ , where τ is the time constant of the circuit. Calculate the rms current for the period t = 0 to t = τ.
An electric bulb is designed to consume 55 W when operated at 110 volts. It is connected to a 220 V, 50 Hz line through a choke coil in series. What should be the inductance of the coil for which the bulb gets correct voltage?
An ac circuit as shown in the figure has an inductor of inductance L and a resistor of resistance R connected in series. Using the phasor diagram, explain why the voltage in the circuit will lead the current in phase.
Answer the following question.
Show that an ideal inductor does not dissipate power in an ac circuit.
In previous questions 3 and 4, what is the net power absorbed by each circuit over a complete cycle. Explain your answer.
At a hydroelectric power plant, the water pressure head is at a height of 300 m and the water flow available is 100 m3 s–1. If the turbine generator efficiency is 60%, estimate the electric power available from the plant (g = 9.8 ms–2).
Quality factor and power factor both have the dimensions of ______.
An alternating current generator has an internal resistance Rg and an internal reactance Xg. It is used to supply power to a passive load consisting of a resistance Rg and a reactance XL. For maximum power to be delivered from the generator to the load, the value of XL is equal to ______.
