Advertisements
Advertisements
Question
What is the value of power factor for a pure resistor connected to an alternating current source ?
Solution
`cos phi = 1 `
`P = VI cos phi` [for LCR Circuit]
For pure resistor
`P = VI therefore [cos phi= 1]`
APPEARS IN
RELATED QUESTIONS
Prove theoretically the relation between e.m.f. induced in a coil and rate of change of magnetic flux in electromagnetic induction.
An A.C. generator generating an emf of ε = 300 sin (100 πt) V is connected to a series combination of 16μ F capacitor, 1 H inductor and 100 Ω resistor.
Calculate :
1) An impedance of the circuit at the given frequency.
2) Resonant frequency `f_0`
3)Power factor at the resonant frequency `f_0`.
The power factor of an a.c. circuit is 0.5. What is the phase difference between voltage and current in this circuit ?
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?
In an AC series circuit, the instantaneous currt is zero when the instantaneous voltage is maximum. Connected to the source may be a
(a) pure inductor
(b) pure capacitor
(c) pure resistor
(d) combination of an inductor and a capacitor
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.
In the series LCR circuit, the power dissipation is through ______
An inductor of reactance 1 Ω and a resistor of 2 Ω are connected in series to the terminals of a 6 V (rms) a.c. source. The power dissipated in the circuit is ______.
An alternating current I = 14 sin (100 πt) A passes through a series combination of a resistor of 30 Ω and an inductor of `(2/(5pi))` H. Taking `sqrt2` = 1.4 calculate the power factor of the circuit.
