1. FDP201X_IIT_BOMBAY OER ACTIVITY KIRAN L INAMDAR
BASIC OF ELECTRICAL ENGINEERING
KIRAN L INAMDAR
PILLAI HOC ENGINEERING/POLYTECHNIC, RASAYANI

2. LEARNING OUTCOME
AT THE END OF THE COURSE STUDENT SHOULD BE ABLE TO UNDERSTAND BASIC CONCEPT OF DC CIRCUITS, MAGNETIC CIRCUITS AND AC CIRCUITS.

3. D.C.CIRCUITS
CURRENT is defined as the motion of electrons or flow of electrons. It is denoted by ( I ) and measure in (A) ampere.
TYPES OF CURRENT :-
A) ALTERNATING CURRENT ( A.C CURRENT)
B) DIRECT CURRENT ( D.C CURRENT )

4. Comparison between AC and DC
Current flowing in power lines and normal household electricity wall outlet is alternating current.
It is defined as a quantity in which direction and magnitude both changes periodically. which changes its Magnitude as well as Direction.
Use of Transformer is Possible.
Frequency 50 Hz.
GENETRATION ,TRASNSIMATION, AND DISTRIBUTION EASY.
Application: AC motors, House-hold etc.
Direct current is produced by sources such as batteries, thermocouples, solar cells, and commutate-type electric machines of the dynamo type.
It is defined as a quantity in which ONLY magnitude changes periodically. which changes its Magnitude
Use of Transformer is NOT Possible.
Frequency is 0 Hz
Generation is difficult.

5. A C CIRCUIT Terminology in a.c. Frequency ( f )
Definition: Number of cycles per second.
Unit: Hertz (Hz)
Period ( T )
Definition: Time required to complete one cycle.
Unit: second (s)
Equation :
Angular frequency
Equation:
Unit: radian per second (rads-1)

6. RMS VALUE
RMS value of an alternating current is defined as it is equivalent value of DC current which when passed through a resistance r ohm for time t sec produces heat which is exactly equals to heat produced when an AC current passed through same resistance r ohm for the same time t sec
I rms =it is ratio of max value to square root 2

7. Formulae i) Capacitive reactance ii) Inductive reactance
iii) Phase angle
iv) Power factor is defined as it is a cosine of phase angle between voltage and current

8. Similarities between EC and MC
Electric Circuit
Magnetic Circuit
A complete path for the current is known as electric circuit.
A complete path for the magnetic flux is called as magnetic circuit.
EMF is the driving force in the electric circuit. Measured in Volts.
MMF is the driving force in the magnetic circuit. Measured in ampere turns.
Current I in the electric circuit which is measured in amperes.
 Flux φ in the magnetic circuit which is measured in the weber.
The flow of electrons decides the current in conductor.
The number of magnetic lines of force decides the flux.
Resistance (R) oppose the flow of the current. Measured in Ohm
Reluctance (S) is opposes creation of magnetic flux. Measured ampere turn/weber.
R = ρ. l/a. Directly proportional to l. Inversely proportional to a. Depends on nature of material.
S = l/ (μ0μra). Directly proportional to l. Inversely proportional to μ = μ0μr. Inversely proportional to a
Ohm’s law and Kirchhoff laws are applicable.

9. Dissimilarities between EC and MC
Electric Circuit
Magnetic Circuit
Energy is required not only to create a current but also to maintain it
Energy is required only to create a flux but not to maintain it
Perfect insulator for electric current are exist.
No insulator for magnetic flux