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The rate of flow of electric charge through any point of the circuit is called electric current. Its unit is ampere.
According to this law, the force of attraction or repulsion between stationary point charges is directly proportional to the product of the charges and inversely proportional to the square of the distance between them.
Where K = 9 X
It is the region surrounding an electric charge or group of charges, in which another charge experiences a force of attraction or repulsion.
It is property of:
ρ = specific resistance or resistivity.
Note: The reciprocal of resistivity is called conductivity.
(Ohm – m)–1 = mho/meter.
Colour Code for Resistances:
NOTE: B. ROY Great Britain Very Good Wife.
Rate of charge of potential w.r.t distance in called potential gradient.
An element in which energy is stored in the form of an electrostatic field is called a capacitor.
Defined as the ratio of charge given to the plate of the capacitor to the potential difference produced between the plate.
Area of Plane
D → Distance between the planes.
∈0 = 8.85 x 10-12
∈0 = Permittivitty of free space.
Unit – c2N–1 M–2
For a capacitor, v ∝ q
Energy stored in a capacitor:
It is an element in which energy is stored in the form of an electromagnetic field (Unit → Henry.)
Energy stored in Inductor:
Inductance results from the fact that a flow of current produces a magnetic field, according to magnetic field along tends to induce a voltage (or current) in a wire according to Faraday's law.
(i) For RL Load :
V=Vm sin wt
show I lags by 90º R-L Load phasor :-
(ii) For RC Load:
Shows I leads by 90º
(iii) For RC phases:
(iv) For RLC Load:
Case 1: |VL| > |Vc|
Case 2: |VL| < |Vc|
Case 3: |VL| = |Vc|
V = VR
Ø = 0
CosØ = 1(UPF)
Note:- Reactive power is consumed by energy storing demands.
|1. What are the basic concepts of Electrical Engineering?|
|2. What is the difference between AC and DC current?|
|3. What are the units of electrical measurement?|
|4. What is the significance of Ohm's Law in Electrical Engineering?|
|5. What are the different types of electrical circuits?|