# Sources Transformation - AC Circuits Flashcards

1
Q

an ideal voltage source in series with an internal resistor, Rs

A

Practical Voltage Source

2
Q

an ideal current source in parallel to an internal resistor Rp

A

Practical Current Source

3
Q

if two practical sources produces the identical values of voltage (Vl) and current (Il) when they are connected to a identical values of Rl

A

Equivalent Practical Source

4
Q

An independent voltage source in series with a resistance, or an independent current source in parallel with a resistance, delivers a maximum power to load resistance Rl for which Rl=Rs

A

Maximum Power Transfer Theorem

5
Q

maximum power formula:

A

Pmax = Vs^2/4Rs = Vth^2/4Rth

6
Q

a signal that has the form of the sine or cosine function

A

Sinusoid

7
Q
• usually referred to as alternating current (ac)
• a current that reverses at regular time intervals and has alternately positive and
negative values
A

Sinusoidal current

8
Q

circuits driven by sinusoidal current or voltage sources

A

AC Circuits

9
Q

A

omega (w)

10
Q

the argument of the sinusoid

A

omega(t) [wt]

11
Q

the amplitude of the sinusoid

A

Vm

12
Q

period of sinusoid

A

T

13
Q

The reciprocal of this quantity is the number of cycles per second, known as…

A

cyclic frequency f

14
Q

phase

A

null sign

15
Q

A ____________may be used to relate or
compare sinusoids as an alternative to using the
trigonometric identities. Also, can be used to add
two sinusoids of the same frequency when one
is in sine form and the other is in cosine form.

A

graphical approach/graphical technique

16
Q

frequency formula

A

f = 1/T

17
Q

period formula:

A

T = 2(pie)/omega

18
Q

a complex number that represents the amplitude and phase of a sinusoid

A

Phasor

19
Q

rectangular form of phasor

A

z = x + jy

20
Q

polar or exponential form of phasor

A

z = r∠∅ = re^j∅

21
Q

is thus the phasor representation of the sinusoid v(t).

A

V

22
Q

complex conjugate

A

z∗ = x − jy = r∠ − ∅ = re^−j∅

23
Q

time domain representation

A

v(t) = Vm cos(ωt + ∅)

24
Q

phasor domain representation

A

V = Vm∠∅

25
Q

the instantaneous or time domain representation

A

v(t)

26
Q

the frequency or phasor domain representation.

A

V

27
Q

time dependent

A

v(t)

28
Q

phasor

A

V = RIm∠∅

29
Q

The ______________ of a circuit is the ratio of the phasor voltage V to the phasor current I, measured in _____________

A

impedance Z, ohms (Ω)

30
Q

It represents the opposition that the circuit exhibits to the flow of sinusoidal current.

A

impedance

31
Q

The ___________ is the reciprocal of impedance, measured in ____________

A