Advertisements
Advertisements
प्रश्न
Draw a graph to show variation of capacitive-reactance with frequency in an a.c. circuit.
Advertisements
उत्तर

where XC is the capacitive-reactance and v is the frequency in an a.c circuit.
APPEARS IN
संबंधित प्रश्न
Reactance of a coil is 157 Ω. On connecting the coil across a source of frequency 100 Hz, the current lags behind e.m.f. by 45°. The inductance of the coil is ...........
(a) 0·25 H
(b) 0·5 H
(c) 4 H
(d) 314H
You are given three circuit elements X, Y and Z. When the element X is connected across an a.c. source of a given voltage, the current and the voltage are in the same phase. When the element Y is connected in series with X across the source, voltage is ahead of the current in phase by π/4 . But the current is ahead of the voltage in phase by π/4when Z is connected in series with X across the source. Identify the circuit elements X, Y and Z. When all the three elements are connected in series across the same source, determine the impedance of the circuit.Draw a plot of the current versus the frequency of applied source and mention the significance of this plot.
Three capacitors of capacities 8 μF, 8 μF and 4 μF are connected in a series and potential difference of 120 volt is maintained across the combination. Calculate the charge on capacitor of capacity 4 μF.
A light bulb is rated at 120 W for a 220 V a.c. supply. Calculate the resistance of the bulb.
What is the reactance of a capacitor connected to a constant DC source?
When the frequency of the AC source in an LCR circuit equals the resonant frequency, the reactance of the circuit is zero. Does it mean that there is no current through the inductor or the capacitor?
Which of the following plots may represent the reactance of a series LC combination?

The reactance of a circuit is zero. It is possible that the circuit contains
(a) an inductor and a capacitor
(b) an inductor but no capacitor
(c) a capacitor but no inductor
(d) neither an inductor nor a capacitor
(i) An alternating emf of 200 V, 50 Hz is applied to an L-R ciruit, having a resistance R of 10 Ω and an inductance L of 0.05H connected in series. Calculate :
(1) Impedance
(2) Current flowing in the circuit
(ii) Draw a labelled graph showing the variation of inductive reactance (`X_L`) verses frequency (`f`) .
In a pure capacitive circuit if the frequency of ac source is doubled, then its capacitive reactance will be ______.
