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Study material for SSE/JE examination by RRB on Electrical Engineering Part I

By on October 6, 2014

Electrical Engineering is an important branch of engineering dealing with Electrical Voltage, Current in DC and AC state, Resistance, Inductance, Capacitance, Generation, Transmission and Utilisation of Electric Power, Electrical Drives etc. This study material is prepared to help those preparing for competition examination.

Part I consists of Fundamental of voltage and current, Resistance, Heating and magnetic effect of current, Magnetic material, Interaction of current-magnetic field-motion, DC motor, DC network theorems, Battery, Battery Charger etc.

Part II consists of AC waveform, Inductor, Transformer, Induction Motor, AC Transmission and Distribution

Fundamentals of Electricity

Electric current: Electric current is the rate of flow of charge (electron) and is also written as dQ/dt. Its unit is Ampere and symbol I. It is similar to rate of flow of water. The speed of electron in a copper conductor is just 0.58 cm/min but it is the electric field or its variation which travels at the speed of light for an electric action to perform.

Electric Potential: Electric Potential is similar to water head which makes water to flow. Electric potential is also accumulation of electric charge at one end and producing an electric field travelling at a speed of light and making the charge to flow through the conductor. Its unit is Voltage and symbol V.

Electrical Earth: Electrical Potential is measured with reference to a universal reference called earth. The earth is having very high capacitance and absorb any amount of charge without raising its potential. A leaking current is disastrous if passed through human being, and therefore, all equipment body is connected to earth. A plug is three pin terminal, of which earth is longer and thick, for the reason of easy identification, earth to connect first and should be able to carry fault current. The neutral is connected to earth at transformer end as well as utilization point.

Ohm’s Law: It is defined that the current through the conductor is directly proportional to voltage applied and constant of proportionality is called Resistance. It is written as V=IR. It is important that there is material which does not follow ohm’s law through out entire temperature range.

Electric Resistance: Flow of electron encounters resistance in its movement and loses its energy. This loss of energy is converted into heat. Unit of resistance is Ohm and symbol Ω. For conductor, a term Conductance is also used to define the property of material which is reversal of resistance (G=1/R) having unit of Siemens.

Series and Parallel combination of Resistance

When resistances are connected in series, then equivalent resistance is given by Req=R1+R2+R3…. and when connected in parallel, it is given by 1/Req= 1/R1+1/R2+1/R3….. Always remember, the resistance increases when connected in series and reduces when in parallel.

Specific Resistance or Resistivity of materials

It is the specific resistance of the material which is specific to the property of the material arising due to the composition of its atomic structure. It is constant for any material, ρ is the symbol and unit Ω-m and calculated by this formula R=ρ*l/A i.e. always remember that the resistance is directly proportional to the length and inversely proportional to the area of cross-section. The resistivity of material varies very largely giving scope for different applications such as conductor, resistor, insulator, semi-conductor etc.

Conductor (x10-8 ohm-meter) : Al(2.8), Brass(6-8), Carbon(3000-7000), Copper(1.72), Gold(2.44), Iron(9.8), Silver(1.64)

Insulator (x10-8 ohm-meter) : Bakelite(1010), Glass(1010-1012), Rubber(1016), Mica(1015), Sulphur (1015)

Heating Element (x10-8 ohm-meter): Tungsten(5.5), Nichrome(108)

Semi-Conductor: Silicon, Germanium

More pages on this topic:

DC Motor (Page 3)

Pages: 1 2 3 4 5 6

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There Are 25 Comments

  1. Shashank says:

    Thanks a lot for this. Waiting eagerly for Mechanical and Civil too..

  2. Abhishek Bhardwaj says:

    Thank you Sir.
    Awaiting mech and civil….

    • Mahesh Kumar Jain says:

      I am an electrical engineer by profession and therefore posted the content of study material sufficient for objective type questions. I hope you know that you have to study electrical as well for civil engineering job exam as well.

  3. sumit butman says:

    Hell sir,
    I just know about you, that u help everyone for his carrier..
    So I need your help.
    (my education qualifications is- 10th passed under WBBSE, after that I am going to complete my diploma course in electrical engg in 2016,)
    I decide to sit in upcoming RRB’s ALP and JE exam..
    Will you please help me to complete the large GK syllabus, because I don’t know from where or which topic of gk comes in rrb exam, or is their any book for rrb’s gk preparation which is recently popular in market? This ‘gk’ is my problem to crack the exam.
    I am so asking because I forget every thing after learning, I like to read by understanding..

    I want make my carrier in Indian railway, pls help me..

    • Mahesh Kumar Jain says:

      It is good that you have decided to prepare on the subject now itself. At this stage, just do following things: 1. Read newspaper daily and makes notes of interested developments. There are many website making questions on the current affairs. Generally current affairs is given importance in any examination. 2. Read your class 8th maths and 9th-10th science books for fundamentals. Develop skills in multiplication tables. Prepare technical notes of your diploma classes which can fit in for multiple choice questions. I will be posting multiple choice questions mock drill tests for people like you to test in between your preparedness.

      • Sumit Burma says:

        Thank you sir,
        Thanks for advise…but according to new syllabus of RRB JE, not only from electrical trade but all trade’s question will be set in the technical part of question. Then my questions is that, how I prepare the other trades question?
        I mean the question will be set from Either all the 3 year’s syllabus of other trades Or only few important subjects of other trades.. Please help me sir.. I have no idea in it..

        If you have any recent RRB JE question paper then please attached it on your website..

        • Mahesh Kumar Jain says:

          The syllabus for JE and SSE as well as Assistant Loco Pilot is same irrespective of the branch he has done his ITI, diploma or Degree. The questions are generally such which one has studied of all the branches. For example while doing BE every one studies some part of the engineering of other branches also. I will be posting the question bank of RRB JE after some time.

  4. Sanket Sharma says:

    Mr.Mahesh Kumar jain could you please tell me which publication or author book is best for preparing RRB sse & je examination for technical & non-technical.

    • Mahesh Kumar Jain says:

      I don’t think any one book can be useful. I suggest you go through the Class IX and X books for JE Science, and Class XI and XII science books for SSE. Read and familiarize with the concept given Class VI and VIII arithmetic. For Technical part, go through your notes prepared during I and II year of study. For other subjects, many books are available. This should be more than sufficient.

  5. Rajesh says:

    hi sir, i would like to know the cutoff marks based on last year notification for SCR SSE & JE.
    And also the inhand salary of them.

    • Mahesh Kumar Jain says:

      I don’t have the cut off of SCR with me. But in any case, you should work of minimum 70% to ensure your making a place in the panel.

  6. Syed Faaique says:

    Sir what was the cut off marks for SSE under general category in 2014 for RRB Secunderabad.

    • Mahesh Kumar Jain says:

      How does it matter Syed? Will it help you in your preparation? Unless you plan for 70%, chances are bleak.

  7. prasanna kumar semili says:

    sir plz can I have last 5 year question paper on following

    • Mahesh Kumar Jain says:

      The examination is not held every year. The question paper is not given to candidate after the examination. During the 2014 examination, the RRB has uploaded the paper on their website. The same are available on this website.

  8. kajal12 says:

    hello sir .. i m a b.e electrical passout. wantd help in tech sction of competative exams. pls help sir. or tell me if there is any you tube channel to help me.

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