# What is j in reactance?

Table of Contents

## What is j in reactance?

In the complex plane multiplying by j means rotating the phasor by 90 degrees ccw; dividing is a 90 degrees cw rotation. Hence the j in the reactances reflect the phase shift of voltage with respect to current in those two ideal cases.

## What does XL XC mean?

XL is called as inductive reactence and Xc is called as capacitive reactence. and the formulae[ XL = 2∏fL, XC = 1/2∏fC ] is given in that website. At resonance the reactence will be same for both cacitence and inductance. That is XL = XC = R.

**What is called reactance?**

Reactance, denoted X, is a form of opposition that electronic components exhibit to the passage of alternating current (alternating current) because of capacitance or inductance. In some respects, reactance is like an AC counterpart of DC (direct current) resistance.

**What causes reactance?**

Reactance is present in addition to resistance when conductors carry alternating current. Reactance also occurs for short intervals when direct current is changing as it approaches or departs from steady flow, for example, when switches are closed or opened. Reactance is of two types: inductive and capacitive.

### Why is j used in impedance?

The j stands in for the imaginary number √(-1). Normally you would use i for this, but j is used in impedance calculations to avoid confusion with I for current.

### Why is j used in electronics?

In electronics, the j-operator signifies the counter-clockwise rotation of a vector. A vector is the non-scalar graphic representation of a complex number, which is made up of a real number and an imaginary number.

**What is XC capacitor?**

Capacitive reactance (Xc) is a measure of a capacitor’s opposition to AC (alternating current).

**Why XL and XC are not considered in DC?**

XL are XC are inductive and capacitive reactance respectively, both are dependent on AC supply frequency as we know DC supply has not freqquency so in DC supply both parameter are not considered.

## What is difference between resistance and reactance?

Mathematically, resistance is simply voltage divided by current. Reactance is a property that opposes a change in current and is found in both inductors and capacitors. Because it only affects changing current, reactance is specific to AC power and depends on the frequency of the current.

## What is difference between reactance and impedance?

Reactances resist currents without dissipating power, unlike resistors. Inductive reactance increases with frequency and inductance. Capacitive reactance decreases with frequency and capacitance. Impedance represents total opposition provided by reactance and resistance.

**How do you stop reactance?**

Instead of flaking on commitments because of a knee-jerk feeling, you can change your perspective on the situation. Here’s a trick: To disarm psychological reactance, change the way you talk to yourself. Instead of thinking you “have to” do something, tell yourself you “get to” or even “deserve to” do it.

**Why is j 90 degrees?**

In terms of circuit theory we will interpret the symbol j when placed in front of a phasor, to mean, advance the phase of the phasor by 90 degrees and -j to mean, retard the phase by 90 degrees. Thus and . We can now redefine impedance as a complex quantity although some times it may be purely real or purely imaginary.

### What is j in Z R jX?

This is the only way to calculate the total impedance of a circuit in parallel that includes both resistance and reactance. Z = R + jX, where j is the imaginary component: √(-1).

### Why do engineers use j and not i?

For example, in electrical engineering and control systems engineering, the imaginary unit is normally denoted by j instead of i, because i is commonly used to denote electric current.

**What is unit of XC?**

The unit of Capacitive Reactance Xc is Ohm.

**Why is there no impedance in DC?**

Since in dc circuit current only goes in one direction i.e. from +ve to -ve end. So, if we use impedance in dc circuit then it won’t allow current to pass through it (if it is capacitive or mixed) or it will get short circuited (if it is inductive) after a fraction of second when impedance coil is fully charged.

## Why inductor is used in DC motor?

An inductor has the property that the current through it cannot change instantaneously, so it can be used as a protection device for current transients (rapid changes in current that can damage components) if used in series with those components.

## What is the difference between inductance and reactance?

Inductance is the ability to create a voltage within a conductor or a nearby conductor by changing the current flow in that the first conductor. Reactance is an opposition to a change in current. Inductance and Reactance are what contribute to reactive power in a system (along with capacitance).