Advertisements
Advertisements
Question
Draw a graph to show variation of capacitive-reactance with frequency in an a.c. circuit.
Solution
where XC is the capacitive-reactance and v is the frequency in an a.c circuit.
APPEARS IN
RELATED QUESTIONS
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
An inductor L of inductance XL is connected in series with a bulb B and an ac source. How would brightness of the bulb change when (i) number of turn in the inductor is reduced, (ii) an iron rod is inserted in the inductor and (iii) a capacitor of reactance XC = XL is inserted in series in the circuit? Justify your answer in each case.
A light bulb is rated at 100 W for a 220 V a.c. supply. Calculate the resistance of the bulb.
A light bulb is rated at 120 W for a 220 V a.c. supply. Calculate the resistance of the bulb.
A light bulb is rated 100 W for 220 V ac supply of 50 Hz. Calculate
(i) The resistance of the bulb;
(ii) The rms current through the bulb.
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?
A coil having self-inductance of 0.7 H and resistance of 165 Ω is connected to an a.c. source of
275V,50Hz. If π = `22/7`
Calculate:
(i) Reactance of the coil
(ii) Impedance of the coil ‘
(iii) Current flowing through the coil
Which of the following graphs represents the correct variation of capacitive reactance Xc with frequency v u?
