Lesson 1&2

Question 1

is an electric current which periodically reverses direction and
changes its magnitude continuously with time

Answer 1

Alternating current (AC)

Question 2

which flows only in one direction.

Answer 2

direct current (DC)

Question 3

as discovered by _____. The process
involves changing magnetic fields inducing an electromotive force (EMF) or voltage in a coil
of wire.

Answer 3

Michael Faraday

Question 4

The value of an alternating quantity
at a particular instant.

Answer 4

Instantaneous Value

Question 5

The maximum value attained by an alternating
quantity during the positive and negative cycle.

Answer 5

Amplitude

Question 6

Is the repetition of a set of positive and negative
value instantaneous values of an alternating quantity.

Answer 6

Cycle

Question 7

It is the time taken by an alternating
quantity to complete one cycle.

Answer 7

Time period

Question 8

the number of completed by an alternating
quantity per second.

Answer 8

Frequency (f)

Question 9

is the frequency expressed in
radians per second

Answer 9

Angular Frequency (ω)

Question 10

are commonly used terms to indicate the magnitude of a periodic signal.
This can be a voltage, current, power or another quantity

Answer 10

average (or mean) and effective (or RMS) values,

Question 11

value of a set of values (or a continuoustime waveform) is the square root of the arithmetic mean of the squares of the values, or the square of the function that defines the
continuous waveform.

Answer 11

RMS

Question 12

current value can also be
defined as the “value of the direct current that dissipates the same
power in a resistor.”

Answer 12

RMS

Question 13

of an alternating quantity is defined as that
value which is obtained by averaging all the instantaneous values over a period of half cycle.

Answer 13

average value

Question 14

is a measure of the relative timing or displacement between two waveforms. It is often expressed in degrees or radians and indicates the time shift between the peaks (or other corresponding points) of two sinusoidal waveforms.

Answer 14

phase angle

Question 15

helps us understand the time relationship between the voltage and current waveforms in such circuits.

Answer 15

phase angle

Question 16

A ____ means that the voltage waveform leads the current waveform

Answer 16

positive phase angle

Question 17

a ___ means that the voltage waveform lags behind the current waveform.

Answer 17

negative phase angle

Question 18

when two waveforms not starting from the same origins are compared, one of them must be lagging the other waveform (or leading the other waveform) assuming they have the same frequencies. Such waveforms are ____ by an angle.

Answer 18

“out of phase”

Question 19

if two waveforms are having the same origin and frequencies, these waveforms are ____ with each other.

Answer 19

“in - phase”

Question 20

is a graphical representation used in electrical engineering to analyze and represent the relationships between different sinusoidal waveforms in AC (alternating current) circuits.

Answer 20

phasor diagram

Question 21

It is a diagram in which different alternating quantities of the same frequency, sinusoidal in nature are represented by individual phasors indicating exact phase interrelationship is known as

Answer 21

phasor diagram