What is the difference between active elements and passive elements

This artile explans the difference betwwen the active elements and passive elements with examples and relative pictures. "A network is an interconnection of two or more elements.If this interconnection involves at least one closed circuit,the network is also called as an electrical circuit".

The classification of network elements are 2 types

1.Active elements
2.Passive elements

    1.Active Elements : The elements which are capable of delivering energy to devices or networks connected across them are known as active elements .
Basically hee are two kinds of active elements as follows .
(i) Independent voltage source
(ii) Independent current source
(i)An independent vootage sourse is a sourse in which the voltage source us a source in which the voltage across the terminals is independent of current passing through it ,

The above figure shows the cicuit representation and V-I characteristics of an ideal sourse.The voltage source is termed as a D.C voltage sourse if it has a constant voltage and is represented as follows ,

The V-I characteristics of a practical voltage source is shown below .

(ii)An independent current sourse is asourse which can deliver a constant current independentof volatge across its terminals.The circuit representation and the V-I characteristics of an ideal current sourse are as shown below.

Practically,the current sourse doesnot posses an ideal behavior .The V-I characteristics of a practical current sourse is as shown below.

2.Passive Elements The elements which cannot deliver power and can only receive the power are known as passive elements.
Basically,there are three kinds of passive elements

(a) Resistor-which absorbs the energy

(b) Inductor-which stores the energy in magnetic field

(c) Capacitor-which stores the energy in an electric field

What is the Difference Between a Current Transformers and a Voltage Transformers ?

The Difference Between a Current Transformers (CT) and a Voltage Transformers(VT) with circuit diagram, A transformer is a device that steps up, or steps down voltage. During this process current is also stepped up or down:however, voltage and current are inversely proportional ( meaning an increase in voltage results in a decrease in current and vice versa ).

current ( 1 amrere ) at the secondary...and a step down transformer with the As an example: A step up transformer of 10:1 ratio with 12 volts and 10 amper of current applied to the primary will have ten times the voltage ( 120 volts ) and ten times less same turns ratio with 120 volts and 1 ampere applied to the primary will have 12 volts and ten ampere available at the secondary. The electricity supplied into homes and bussiness uses wires carrying very high voltage and low current over long distances, then uses step down transformers to step down the voltage and step up the current. 

However, in power engineering and protective relaying applications, there are what are called "instrument transformers" which have the specific purpose of providing information to devices (such as relays or meters) about the voltages or currents in the power system. Therefore, there are some differences in construction and connectivity between a Current Transformer (CT) and a Voltage (or Potential) Transformer (PT).

 A CT will typically have a toroidal core and evenly distributed secondary windings so as to minimize leakage reactance. The primary is typically the main power line conductor, which passes directly through the toroidal core. This type of transformer is specifically for the purpose of measuring current values, and the secondary windings cannot be left open-circuited, or a large voltage will be produce, resulting in dielectric failure (and often an explosion). If a device is not connected to the CT, its secondary must be short-circuited. 

A PT is connected between the main conductor and ground and can be either wound in the normal way, or the voltage can be taken from a subsection of a string of capacitors (this is called a Capacitive Voltage Tansformer or CVT, and is usually cheaper than the wound type, but is typically not as accurate). This type of transformer measures voltage values, and the secondary winding cannot be short-circuited, as this will produce excessively high currents, resulting in the failure of the PT or the wires it is connected to. A PT can be left open-circuited. 

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Differences Between C.T and P.T 

CURRENT TRANSFORMER	POTENTIAL TRANSFORMER
The secondary of a C.T can not be open circuited on any circumstance when it is under service.	The secondary of  a P.T can be open circuited without any damage being caused either to the operator or the transformer.
A CT may be considered as a series transformer.	P.T may be considered as a parallel transformer.
The primary current in a C.T is independent of the secondary circuit conditions (burden).	The primary current of a P.T depends upon the secondary circuit conditions (burden).
The primary winding of the CT is connected in series with the line carring the current to be measured. Hence it carries of the full line current.	The primary winding P.T is connected across the line of voltage to be measured. Hence the full line voltage is impressed across its terminal.
With the help of CT, a 5A ammeter can be used measure a high current like 200A.	With the help of P.T, a 120V voltmeter can be used to measure very high voltages like 11KV.