Basic Electrical Concepts | Electrical Engineering SSC JE (Technical) - Electrical Engineering (EE) PDF Download

Some of the Basic Concepts include :

1. Electric Current

The rate of flow of electric charge through any point of the circuit is called electric current. Its unit is ampere, denoted by A.

Basic Electrical Concepts | Electrical Engineering SSC JE (Technical) - Electrical Engineering (EE)

2. Coulomb's Law

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.

Basic Electrical Concepts | Electrical Engineering SSC JE (Technical) - Electrical Engineering (EE)

Basic Electrical Concepts | Electrical Engineering SSC JE (Technical) - Electrical Engineering (EE)

Where K = 9 X    Basic Electrical Concepts | Electrical Engineering SSC JE (Technical) - Electrical Engineering (EE)

Basic Electrical Concepts | Electrical Engineering SSC JE (Technical) - Electrical Engineering (EE)N

Basic Electrical Concepts | Electrical Engineering SSC JE (Technical) - Electrical Engineering (EE)

Question for Basic Electrical Concepts
Try yourself:What is the unit of electric current?
View Solution

3. Electric Field

It is the region surrounding an electric charge or group of charges, in which another charge experiences a force of attraction or repulsion.

Basic Electrical Concepts | Electrical Engineering SSC JE (Technical) - Electrical Engineering (EE)

4. Electric Lines of Forces

  • An electric lines of force field along which a free isolated unit positive charge moves.
  • Electric lines of force start from the positive charge and end to the negative charge.
  • No two lines of force can intersect each other because if they do so, then at the point of intersection two tangents can be drawn which would mean two directions of force at that point which is impossible.
  • These lines have a tendency to separate from each other in the direction perpendicular to their length.
  • Lines of force of uniform field are parallel.
  • Lines of force leaves the surface of the conductor normally.

Question for Basic Electrical Concepts
Try yourself:
What is the purpose of electric lines of force?
View Solution

1 Crore+ students have signed up on EduRev. Have you? Download the App

5. Electric Flux

The total number of the electric field lines passing a given area in the unit of time is known as the electric flux.Basic Electrical Concepts | Electrical Engineering SSC JE (Technical) - Electrical Engineering (EE)

When the plane is irregular at an angle θ, then the projected area is Acosθ, and the total flux through this surface is given as-Basic Electrical Concepts | Electrical Engineering SSC JE (Technical) - Electrical Engineering (EE)

Where,

E = Magnitude of the electric field.

A = Area of the surface through which the electric flux is calculated.

θ = The angle made by the axis and the plane that is parallel to the direction of flow of an electric field.

Unit of Electric Flux

  • V . m
  • Nm m²C⁻¹
  • Base unit: Kg. m³s⁻³A⁻¹

6. Ohm's Law

According to this law if there is no charge the physical state of conductor (Such as temp.) then the current flowing through the conductor is directly proportional to the voltage applied i, e.

I α V .

I = Basic Electrical Concepts | Electrical Engineering SSC JE (Technical) - Electrical Engineering (EE)Basic Electrical Concepts | Electrical Engineering SSC JE (Technical) - Electrical Engineering (EE)

  • V is the potential difference measured across the conductor (in volts)
    I  is the current through the conductor (in amperes)
    R is the constant of proportionality called resistance (in ohms)
  • A graph between applied voltage and current is a straight line shows that it follows ohm's law.
  • Ohm's law is valid for metallic conductors only.

7. Resistance

It is a measure of opposition to the flow of electric current.

Electrical resistance is directly proportional to length (L) of the conductor and inversely proportional to the cross-sectional area (A). It is given by the following relation.Basic Electrical Concepts | Electrical Engineering SSC JE (Technical) - Electrical Engineering (EE)

Note:The reciprocal of resistivity is called conductivity.

Basic Electrical Concepts | Electrical Engineering SSC JE (Technical) - Electrical Engineering (EE)  (Ohm – m)–1 = mho/meter.

Colour Code for Resistances:

  • Resistor colour codes, introduced by the Radio Manufacturers Association (RMA) in the 1920s, are used to represent resistance values, tolerance, and sometimes reliability on tiny resistors, typically up to one watt. These codes consist of 3 to 6 colour bands, with the first two indicating resistance value, the third as a multiplier, and additional bands specifying tolerance or reliability. This system simplifies reading resistance values without requiring printed numbers.
  • These resistances are usually carbon resistances and whose code is used to indicate the value of resistance. 
  • A carbon resistance has usually 4 concentric rings or bands A, B, C, D of different colours.
    Basic Electrical Concepts | Electrical Engineering SSC JE (Technical) - Electrical Engineering (EE)
  • The colour of first two bands A and B indicate the 1st two significant figures of resistance in ohms & those of 3rd band C indicate the decimal multiplies. The 4th band D (Which is either silver or gold) tells the tolerance. 
  • Sometimes only 3 colour band is there (A, B and C).

NOTE: B B ROY Great Britain Very Good Wife.   

Resistor colour tableResistor colour table

8. Electric Potential

The electric potential at a point in an electric field is the ratio of the work done in bringing a test charge from infinity to that point to the magnitude of the test change. 

If the work done in moving a test charge q0 from infinity to that point against the field is W, then
Basic Electrical Concepts | Electrical Engineering SSC JE (Technical) - Electrical Engineering (EE)Basic Electrical Concepts | Electrical Engineering SSC JE (Technical) - Electrical Engineering (EE)

9. Potential Gradient

The potential gradient is the rate of change of electric potential with respect to distance in an electric field. It is mathematically expressed as:Basic Electrical Concepts | Electrical Engineering SSC JE (Technical) - Electrical Engineering (EE)

Basic Electrical Concepts | Electrical Engineering SSC JE (Technical) - Electrical Engineering (EE)

Download the notes
Basic Electrical Concepts
Download as PDF
Download as PDF

10. Electric Potential Energy

The electric potential energy of a system of charges is the work that has to be done in bringing these charges from infinity to near each other to form the system.

The potential energy of a system of charges q1 and q2 separated by a distance 'r' is
Basic Electrical Concepts | Electrical Engineering SSC JE (Technical) - Electrical Engineering (EE)

11. Capacitor

An element in which energy is stored in the form of an electrostatic field is called a capacitor.

  •  It functions similarly to a rechargeable battery. 
  • Capacitors come in various types, including small beads used in resonance circuits and larger ones for power factor correction. 
  • Despite their differences, all capacitors serve the same purpose of energy storage.
  •  Essentially, a capacitor consists of two or more conductive plates that are not connected or in contact with each other.

Practical CapacitorPractical Capacitor

Capacitor Circuit diagramCapacitor Circuit diagram


12. Capacitance

  • Capacitance refers to a capacitor's ability to store electrical energy and is measured in farads, a unit named after the British physicist Michael Faraday.
  •  It is defined as the ability of a capacitor to store one coulomb of charge to create a 1-volt potential difference. Basic Electrical Concepts | Electrical Engineering SSC JE (Technical) - Electrical Engineering (EE)
  •  Since the farad is a large unit, capacitance is often measured in smaller units such as pico-farads, nano-farads, and micro-farads.
  • Basic Electrical Concepts | Electrical Engineering SSC JE (Technical) - Electrical Engineering (EE)
  • The physical features of a capacitor determine the value of its capacitance – the area of the capacitor, the distance between the plates of the capacitor, and the dielectric medium’s permittivity, 0 = 8.85 x 10-12 
  • Unit – C2N–1 M–2
Take a Practice Test
Test yourself on topics from Electrical Engineering (EE) exam
Practice Now
Practice Now

Energy stored in a capacitor:

Energy(E) =  Basic Electrical Concepts | Electrical Engineering SSC JE (Technical) - Electrical Engineering (EE)

=   Basic Electrical Concepts | Electrical Engineering SSC JE (Technical) - Electrical Engineering (EE)

= C.  Basic Electrical Concepts | Electrical Engineering SSC JE (Technical) - Electrical Engineering (EE)

Basic Electrical Concepts | Electrical Engineering SSC JE (Technical) - Electrical Engineering (EE)

13. Inductor

An inductor is a component that does not require power to operate and is commonly used in various power electronic circuits

  • Its main function is to store energy as magnetic energy when electricity flows through it. 
  • The unit of measurement for inductance is the Henry
  •  The key characteristic of an inductor is its inductance, which is defined as the ratio of the voltage across it to the rate at which the current changes. This inductance arises from the magnetic field created around the coil of wire. 
  • Several factors influence the level of inductance, including: 
    • The shape of the coil.
    • The number of turns and layers of wire in the coil.
    • The spacing between the turns of wire.
    • The permeability of the core material used.
    • The size of the core itself.

One henry is defined as the inductance of a coil in which a change in current of one ampere per second induces a voltage of one volt.

Formula:The inductance LLL of an inductor is given by the formula:

L=N2μA / lL = \frac{{N^2 \mu A}}{{l}}

Where:

  • L = Inductance (in henries, H)
  • N = Number of turns in the coil
  • μ = Permeability of the core material (in henries per meter, H/m)
  • A = Cross-sectional area of the coil (in square meters, m²)
  • ll = Length of the coil (in meters, m)

For a simple circuit, the induced voltage VV is related to the rate of change of current Basic Electrical Concepts | Electrical Engineering SSC JE (Technical) - Electrical Engineering (EE)\frac{di}{dt} by:

Basic Electrical Concepts | Electrical Engineering SSC JE (Technical) - Electrical Engineering (EE)V = L \cdot \frac{di}{dt}Where:

  • VV = Induced voltage (in volts, V)
  • LL = Inductance (in henries, H)
  • di / dt\frac{di}{dt}= Rate of change of current (in amperes per second, A/s)

Energy stored in Inductor:

Basic Electrical Concepts | Electrical Engineering SSC JE (Technical) - Electrical Engineering (EE)

= L.  Basic Electrical Concepts | Electrical Engineering SSC JE (Technical) - Electrical Engineering (EE)

Question for Basic Electrical Concepts
Try yourself:What is the unit of electric flux?
View Solution

14. Inductance

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.

Basic Electrical Concepts | Electrical Engineering SSC JE (Technical) - Electrical Engineering (EE)

(i) For RL Load :

V=Vm sin wt

Basic Electrical Concepts | Electrical Engineering SSC JE (Technical) - Electrical Engineering (EE)

Basic Electrical Concepts | Electrical Engineering SSC JE (Technical) - Electrical Engineering (EE)

show I lags by 90º R-L Load phasor :-

Basic Electrical Concepts | Electrical Engineering SSC JE (Technical) - Electrical Engineering (EE)
Basic Electrical Concepts | Electrical Engineering SSC JE (Technical) - Electrical Engineering (EE)Basic Electrical Concepts | Electrical Engineering SSC JE (Technical) - Electrical Engineering (EE)

(ii) For RC Load:

Basic Electrical Concepts | Electrical Engineering SSC JE (Technical) - Electrical Engineering (EE)

Basic Electrical Concepts | Electrical Engineering SSC JE (Technical) - Electrical Engineering (EE)

Shows I leads by 90º

(iii) For RC phases:

Basic Electrical Concepts | Electrical Engineering SSC JE (Technical) - Electrical Engineering (EE)

Basic Electrical Concepts | Electrical Engineering SSC JE (Technical) - Electrical Engineering (EE)
Basic Electrical Concepts | Electrical Engineering SSC JE (Technical) - Electrical Engineering (EE)

(iv) For RLC Load:

Case 1: |VL| >  |Vc|
Basic Electrical Concepts | Electrical Engineering SSC JE (Technical) - Electrical Engineering (EE)

Basic Electrical Concepts | Electrical Engineering SSC JE (Technical) - Electrical Engineering (EE)

Case 2: |VL| <  |Vc|

Basic Electrical Concepts | Electrical Engineering SSC JE (Technical) - Electrical Engineering (EE)


Basic Electrical Concepts | Electrical Engineering SSC JE (Technical) - Electrical Engineering (EE)

Case 3: |VL| =  |Vc|

V = VR

Ø = 0

CosØ = 1(UPF)

Note:- Reactive power is consumed by energy storing demands.

The document Basic Electrical Concepts | Electrical Engineering SSC JE (Technical) - Electrical Engineering (EE) is a part of the Electrical Engineering (EE) Course Electrical Engineering SSC JE (Technical).
All you need of Electrical Engineering (EE) at this link: Electrical Engineering (EE)
Are you preparing for Exam? Then you should check out the best video lectures, notes, free mock test series, crash course and much more provided by EduRev. You also get your detailed analysis and report cards along with 24x7 doubt solving for you to excel in exam. So join EduRev now and revolutionise the way you learn!
Sign up for Free Download App for Free
23 videos|89 docs|42 tests

Up next

FAQs on Basic Electrical Concepts - Electrical Engineering SSC JE (Technical) - Electrical Engineering (EE)

1. What are the basic concepts of electrical engineering?
Ans. Electrical engineering deals with the study and application of electricity, electronics, and electromagnetism. It includes concepts such as voltage, current, resistance, circuits, and electromagnetic fields.
2. What is the difference between AC and DC electricity?
Ans. AC (alternating current) electricity changes direction periodically, while DC (direct current) electricity flows in one direction continuously. AC is commonly used in households, while DC is used in batteries and electronic devices.
3. What is Ohm's Law and how is it used in electrical engineering?
Ans. Ohm's Law states that the current flowing through a conductor is directly proportional to the voltage across it and inversely proportional to its resistance. It is used to calculate current, voltage, and resistance in electrical circuits.
4. What are the different types of electrical circuits?
Ans. There are two main types of electrical circuits: series circuits, where components are connected in a single path, and parallel circuits, where components are connected in multiple paths. Combination circuits consist of a mix of series and parallel components.
5. How is power calculated in electrical engineering?
Ans. Power in an electrical circuit is calculated using the formula P = VI, where P is power in watts, V is voltage in volts, and I is current in amperes. This formula can also be used in conjunction with Ohm's Law to calculate power in terms of voltage and resistance or current and resistance.
23 videos|89 docs|42 tests
Download as PDF

Up next

Explore Courses for Electrical Engineering (EE) exam
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
10M+ students study on EduRev
Related Searches

pdf

,

Objective type Questions

,

Semester Notes

,

Exam

,

Free

,

Important questions

,

past year papers

,

Viva Questions

,

mock tests for examination

,

Summary

,

Previous Year Questions with Solutions

,

MCQs

,

Sample Paper

,

practice quizzes

,

Basic Electrical Concepts | Electrical Engineering SSC JE (Technical) - Electrical Engineering (EE)

,

ppt

,

study material

,

video lectures

,

Basic Electrical Concepts | Electrical Engineering SSC JE (Technical) - Electrical Engineering (EE)

,

shortcuts and tricks

,

Extra Questions

,

Basic Electrical Concepts | Electrical Engineering SSC JE (Technical) - Electrical Engineering (EE)

;