Advertisements
Advertisements
प्रश्न
An alternating voltage of 220 V is applied across a device X. A current of 0.22 A flows in the circuit and it lags behind the applied voltage in phase by π/2 radian. When the same voltage is applied across another device Y, the current in the circuit remains the same and it is in phase with the applied voltage.
- Name the devices X and Y and,
- Calculate the current flowing in the circuit when the same voltage is applied across the series combination of X and Y.
Advertisements
उत्तर
- X is a resistor and Y is the capacitor.
R = `V_{rms}/I_{rms} = 220/0.22 = 1000 Omega`
R = XC = 1000Ω
When R and C are in series.
`I_{rms} = V_{rms}/Z = V_{rms}/sqrt(R^2 + (X_C)^2)`
= `220/sqrt((1000)^2 + (1000)^2)`
= `220/(1000 xx sqrt2)`
`I_{rms} = 0.156` A
APPEARS IN
संबंधित प्रश्न
In a series LCR circuit connected to an a.c. source of voltage v = vmsinωt, use phasor diagram to derive an expression for the current in the circuit. Hence, obtain the expression for the power dissipated in the circuit. Show that power dissipated at resonance is maximum
A series LCR circuit is connected across an a.c. source of variable angular frequency 'ω'. Plot a graph showing variation of current 'i' as a function of 'ω' for two resistances R1 and R2 (R1 > R2).
Answer the following questions using this graph :
(a) In which case is the resonance sharper and why?
(b) In which case in the power dissipation more and why?
An inductor-coil of inductance 17 mH is constructed from a copper wire of length 100 m and cross-sectional area 1 mm2. Calculate the time constant of the circuit if this inductor is joined across an ideal battery. The resistivity of copper = 1.7 × 10−8 Ω-m.
The magnetic field at a point inside a 2.0 mH inductor-coil becomes 0.80 of its maximum value in 20 µs when the inductor is joined to a battery. Find the resistance of the circuit.
In an LCR series a.c. circuit, the voltage across each of the components, L, C and R is 50V. The voltage across the LC combination will be ______.
At resonance frequency the impedance in series LCR circuit is ______.
At resonant frequency the current amplitude in series LCR circuit is ______.
A series LCR circuit containing a 5.0 H inductor, 80 µF capacitors, and 40 Ω resistor is connected to a 230 V variable frequency ac source. The angular frequencies of the source at which power is transferred to the circuit are half the power at the resonant angular frequency are likely to be ______.
If the rms current in a 50 Hz ac circuit is 5 A, the value of the current 1/300 seconds after its value becomes zero is ______.
Draw the phasor diagram for a series LRC circuit connected to an AC source.
