Advertisements
Advertisements
Question
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.
Solution
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
RELATED QUESTIONS
A lamp is connected in series with an inductor and an AC source. What happens to the brightness of the lamp when the key is plugged in and an iron rod is inserted inside the inductor? Explain.
For a given a.c., i = im sin ωt, show that the average power dissipated in a resistor R over a complete cycle is `1/2I_m^2` R .
In a circuit, containing a capacitor and an AC source, the current is zero at the instant the source voltage is maximum. Is it consistent with Ohm's Law?
A coil has a resistance of 10 Ω and an inductance of 0.4 henry. It is connected to an AC source of 6.5 V, `30/pi Hz`. Find the average power consumed in the circuit.
In a series LCR circuit with an AC source, R = 300 Ω, C = 20 μF, L = 1.0 henry, εrms = 50 V and ν = 50/π Hz. Find (a) the rms current in the circuit and (b) the rms potential difference across the capacitor, the resistor and the inductor. Note that the sum of the rms potential differences across the three elements is greater than the rms voltage of the source.
Suppose the circuit has a resistance of 15 Ω. Obtain the average power transferred to each element of the circuit, and the total power absorbed.
In which of the following circuits the maximum power dissipation is observed?
Quality factor and power factor both have the dimensions of ______.
The coefficient of induction of a choke coil is 0.1 H and resistance is 12 Ω. If it is connected to an a.c source of frequency 60Hz. Then the power factor will be ______.
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 ______.
