Advertisements
Advertisements
प्रश्न
An ac circuit consists of a series combination of circuit elements X and Y. The current is ahead of the voltage in phase by `pi/4`. If element X is a pure resistor of 100 Ω,
(a) name the circuit element Y.
(b) calculate the rms value of current, if rms of voltage is 141 V.
(c) what will happen if the ac source is replaced by a dc source
Advertisements
उत्तर
(a) We have,

Φ = π/4
tan Φ = 1
`tanphi = "Reactance"/"Resistance"`
Reactance = Resistance
Y = 100 Ω
As, ϕ > 0°, means voltage ahead of current Hence element Y is an Inductor.
(b)
`"R.m.s value of current" = "R.m.s value of voltage"/"Impedance"`
`"i"_"Rms" = 141/sqrt((100)^2+ (100)^2)`
`"i"_"Rms" = 141/(100sqrt2) = 141/(100 xx 1.41)`
iRms = 1 A
(c) If the Ac is Replace by DC, then the Inductor will behave as a short circuit, and the circuit will be purely Resistive.

APPEARS IN
संबंधित प्रश्न
Two capacitors of unknown capacitances C1 and C2 are connected first in series and then in parallel across a battery of 100 V. If the energy stored in the two combinations is 0.045 J and 0.25 J respectively, determine the value of C1 and C2. Also calculate the charge on each capacitor in parallel combination.
Deduce an expression for equivalent capacitance C when three capacitors C1, C2 and C3 connected in parallel.
A circuit is set up by connecting inductance L = 100 mH, resistor R = 100 Ω and a capacitor of reactance 200 Ω in series. An alternating emf of \[150\sqrt{2}\] V, 500/π Hz is applies across this series combination. Calculate the power dissipated in the resistor.
The following figure shows two capacitors connected in series and joined to a battery. The graph shows the variation in potential as one moves from left to right on the branch containing the capacitors.

A parallel-plate capacitor is connected to a battery. A metal sheet of negligible thickness is placed between the plates. The sheet remains parallel to the plates of the capacitor.
A parallel-plate capacitor having plate area 25 cm2 and separation 1⋅00 mm is connected to a battery of 6⋅0 V. Calculate the charge flown through the battery. How much work has been done by the battery during the process?
Find the charges on the four capacitors of capacitances 1 μF, 2 μF, 3 μF and 4 μF shown in the figure.

Three different capacitors are·connected in series. Then:-
In the circuit shown in figure, initially K1 is closed and K2 is open. What are the charges on each capacitors.
Then K1 was opened and K2 was closed (order is important), What will be the charge on each capacitor now? [C = 1µF]
