Which of the following statements is not correct for a pure inductive circuit?
(A) The power factor of the circuit is zero answer : power factor is R/Z ; if R is zero , then p.f. is zero (B) The power consumed in the circuit is zero answer : if R is zero , then power P = R*I^2 is zero (C) The instantaneous power in the circuit can have any value positive, negative or zero answer : instantaneous power is a sinus having twice the net frequency, average value zero as any sinus, and any instantaneius value in the p.u. range 0.5..0..-0.5 (D) All of the above statements are true for a pure inductive circuit answer : all previos statements are true !!!!
Which of the following statements is not correct for a pure inductive circuit?
(A) The power factor of the circuit is zero answer : power factor is R/Z ; if R is zero , then p.f. is zero (B) The power consumed in the circuit is zero answer : if R is zero , then power P = R*I^2 is zero (C) The instantaneous power in the circuit can have any value positive, negative or zero answer : instantaneous power is a sinus having twice the net frequency, average value zero as any sinus, and any instantaneius value in the p.u. range 0.5..0..-0.5 (D) All of the above statements are true for a pure inductive circuit answer : all previos statements are true !!!!
Which of the following statements is correct when made in reference to a parallel circuit?
A is not true. In a parallel circuit, the same potential exists across each branch, and the current in each branch is dependent on only that branch's impedance. B is not true because it is an incorrect interpretation of Ohm's law. Current is voltage divided by impedance. C is true, because of Kirchoff's current law. The current entering a node (in this case the parallel circuit itself) is equal to the current leaving that node. D is true of a series resistor circuit, but not of a parallel circuit.
If the frequency of the pure inductive circuit is half the current of the circuit will be..?
It Doubles. 20 Ohms. Xc=1/(2 *(pi)*f*C) Where Xc is Reactive Capacitance, f is frequency and C is capacitance in Farads. Using the numbers you gave. 10= 1/ (2 * 3.142 * 100 * C) C=1.59E-4 Substitute C back in Using 50 as f, solve for Xc. Xc= 1/ (2 * 3.142 * 50* 1.59E-4) Xc=20
What is a purely resistive AC circuit?
Purely resistance circuits consist of electrical devices, which contain no inductance or capacitance. Devices such as resistors, lamps ( incandescent ) and heating elements have negligible inductance or capacitance and for practical purposes can be considered to be purely resistive. For such AC circuits the same rules and laws apply as for DC circuits.When an AC circuit contains only resistive devices, Ohms Law, Kirchoff’s Laws, and the Power Laws can be used in exactly the same way as in DC circuits.For more datils check our fb page...https://m.facebook.com/Electrica...For ASK more questions , contact us on fb...https://facebook.com/ElectricalE...
What is the phase of the voltage relative to current at resonance?
I'm going to use the concept of perfect components for this. So an inductor has no resistance or capacitance, a resistor has no capacitance or inductance, and a capacitor has no resistance or inductance.Remember ELI the ICE man.In an inductor "L", EMF or voltage leads I or current.In a capacitor "C", I or current leads EMF or voltage.E is actually supposed to be the symbol for voltage like I is the symbol for current in equations. Not to be confused with the units voltage V and amperes A.What leads or lags depends on if it is a series or parallel RLC circuit.In parallel circuits, voltage is the same across all components. At resonance, current in the resistor is in phase with the applied voltage. Current in the inductor will lag the applied voltage by 90 degreees. Current in the capacitor will lead the applied voltage by 90 degrees. Since the current in the inductor and capacitor are 180 degrees out of phase of each other, the only current that flows in and out of the circuit is that of the resistor.In series circuits, current is the same through all components. At resonance, voltage across the resistor is in phase with the applied current. Voltage across the inductor will lead the applied current by 90 degrees. Voltage across the capacitor will lag the applied current by 90 degrees. Since the voltages across the inductor and capacitor are 180 degrees out of phase with each other, they cancel and only the voltage across the resistor appears outside the circuit.
Why does current lead voltage in a capacitive circuit?
There's a mathematical explanation, and there's an intuitive one. Let's do the mathematical explanation first:Looking at the circuit above, we know for a capacitor that Q = CVwhere Q is the charge on the capacitor's plates, C is its capacitance, and V is the voltage across the capacitor.We also know that I, the electric current is the flow of electric charge with time:I = dQ/dtCombine these two, and for a capacitor, we see:I = dQ/dt = C*dV/dtNow, if we have a sinusoidal input voltage, we can calculate the current across the capacitor as a function of the voltage:V(t) = sin(t)I(t) = C*dV(t)/dt = C*cos(t)But cos(t) is just sin(t) plus pi/2 radians (90 degrees). So our final equations for the capacitor circuit above become:V(t) = sin(t)I(t) = C*cos(t) = C*sin(t + pi/2)So for a sinusoidal input voltage, we see that we also get a sinusoidal current, but the current leads the voltage by pi/2 radians (90 degrees)!And the intuitive explanation:Intuitively, we know the current through a capacitor can change instantaneously, but since its voltage is determined by the sum of all the charge that has flowed through it, the voltage reacts less quickly. For example, a large but very short spike in current may lead to only a small change in the voltage. This means that, for a capacitor, changes in voltage will always lag behind changes in current.I hope this was helpful!Useful links:AC CIRCUITS is the site where I got the above image. It also has a decent intro to other circuits not mentioned here, including an intro to analysis in the frequency domain, which I didn't cover.