Contents
How do you calculate reactance?
The formula for calculating the inductive reactance of a coil is: inductive reactance, or XL, is the product of 2 times p (pi), or 6.28, the frequency of the ac current, in hertz, and the inductance of the coil, in henries. XL =2p x f x L. L = the inductance value of the coil in henries.
How do you calculate resistance from reactance?
Z = [(Xc-XL)^2 + R]^0.5, where Z is the impedence, Xc is reactance of the capacitor which is equal to 1/(wC), w being the angular frequency and C being capacitance. XL is reactance of the coil which is equal to wL, L being the inductance of the coil, and R is resistance of the coil.
Can ever RMS value be equal to peak value of an AC?
Yes, when the a.c. is a square wave, r.m.s value, average value and peak value of a.c. are equal Choiec (d) is correct.
How to calculate the RMS voltage of an element?
Calculate the rms voltage across each element by multiplying the reactance or resistance of each element by the rms current. To calculate the rms current, divide the rms voltage by the impedance, given by equation 24 -16.
Which is the RMS value of short circuit making current?
Since RMS value of steady state short circuit current is called breaking current so short circuit making current can be written as: Above expression for calculating the making current is also given by Indian standard 10118, part-2 for selection, installation and maintenance of switchgear and controlgear.
When does the reactance of a short circuit increase?
Reactance in this state is called steady state reactance and is denoted by Xd. Here we can introduce the concept of short circuit making and breaking current. During the first few cycles of fault current the reactance is least and magnitude of short circuit current is highest. Current increases to maximum value at the peak of first current loop.
Why is the RMS current limited by the capacitor?
Since an AC voltage is applied, there is an rms current, but it is limited by the capacitor. This is considered to be an effective resistance of the capacitor to AC, and so the rms current I in the circuit containing only a capacitor C is given by another version of Ohm’s law to be