BASIC ELECTRICAL A/C DEFINITION AND SINUSOIDAL VOLTAGE GENERATION.

1. Gandhinagar Institute Of Technology
Active Learning Assignment
Subject :- Elements Of Electrical Engineering(21100005)
Topic :- Basic Electrical A/C Definition And Generation Of
Sinusoidal Voltage
Branch :- Mechanical Engg.
Batch :- K-1
Presented by:
1)Patel Jaydev (150120119127)
2)Patel Parth .V (150120119132)
3)Patel Parth .R (150120119133)
Guided by:- Prof. Grishma Pipaliya

2. Generation Of
Sinusoidal Voltage

3. Generation Of Sinusoidal Voltage
 As seen in the video we can produce sinusoidal voltage in
two ways:
1) By rotating coil in a stationary magnetic field or
2) By a rotating magnetic field with a stationary coil.
 Hence according to faraday’s law of electromagnetic
induction emf is induced in a coil, due to change in
magnetic flux with time.
 And the induced emf depends upon the following :
1) No. of turns of coil
2) Angular velocity of coil in a stationary magnetic field.
3) Also due to change in flux.

4.  As per faraday’s law emf induced in a coil is negative of
change in flux.
e =- N
=
=
Thus, for
1) t=o e=0 2) t=90 e=maximum
e=E
The negative sign is due to lenz’s law:
The direction of induced emf is such that it opposes the
change that caused it.

5. The mathematical description of the sinusoid
includes the peak amplitude and the angular
frequency and may include a phase angle.
RMS values of a sinusoid are calculated using the formula
 Phase angle for a sinusoid is calculated with
respect to a reference.

6. RMS Value:
 RMS Value:
The steady current which when flowing through a given
resistor for a given time produces the same amount of
heat as is produced by the alternating current when
flowing through the same resistor for the same time is
called R.M.S or effective value of the AC.
 In electrical mainly for AC we are always take R.M.S
value or Effective values for calculation.
 Suppose we say the supply voltage in house 230volts,
it means that the R.M.S value of the supply voltage is
230volts.

7. Application:
 Attempts to find an average value of AC would
directly provide you the answer zero... Hence, RMS
values are used. They help to find the
effective value of AC (voltage or current).
This RMS is a mathematical quantity (used in many
math fields) used to compare both alternating and
direct currents (or voltage).

8. Average Value:
 Average Value:
 The average value of AC is defined as the D.C current
which transfers across any circuit the same charge as
is transferred by that AC during the same time..
 Average value of AC=2/π*Im

9. Form Factor:
 In electronics, the form factor of an alternating
current waveform (signal) is the ratio of the RMS
(root mean square) value to the average value
 It identifies the ratio of the direct current of equal
power relative to the given alternating current. The
former can also be defined as the direct current that
will produce equivalent heat.

10. Calculation of Form Factor:

11. Application:
 Digital AC measuring instruments are often built with
specific waveforms in mind. For example, many
digital AC multimeters are specifically scaled to
display the RMS value of a sine wave. Since the RMS
calculation can be difficult to achieve digitally, the
absolute average is calculated instead and the result
multiplied by the form factor of a sinusoid. This
method will give less accurate readings for waveforms
other than a sinewave.

12. Peak Factor:
 The Peak Factor is defined as the ratio of maximum
value to the R.M.S value of an alternating quantity.