AC Circuits Analysis

Question 1

For the resistanc are voltage and current in phase or not?

Answer 1

They are in phase

Question 2

For the inductance, L are voltage and current in phase or not?

Answer 2

They are not in phase I lags V by 90° or pi/2 in rads

Question 3

For the capacitance , C are voltage and current in phase or not?

Answer 3

They are not in phase I leads ᵛ by 90° or pi/2 in rads

Question 4

What is inductive reactance ad its symbol

Answer 4

X subscript l
The opposition of flow of current by an inductor in an ac sinusoidal circuit

Question 5

What is capacitive reactance ad its symbol

Answer 5

X subscript c
The opposition of flow of current by a capacitor in an ac sinusoidal circuit

Question 7

What is impedance?

Answer 7

The flow of ac through a circuit with a combination of resistance and reactance

Question 8

Impedance symbol

Answer 8

Z

Question 9

For steady state circuit analysis what is expressed in phaser and what is expressed in. Complex impedance

Answer 9

Phasor- voltage current. V I
Complex impedance/ resistor, capacitor and inductors

Question 10

X꜀

Answer 10

1/cω

Question 11

Xₗ

Answer 11

ωL

Question 12

What function makes the circuit in time domain

Answer 12

Voltage that varies with time v(t)

And

Current that varies with time i (t)

Question 13

What function makes the circuit in frequency domain

Answer 13

When the circuit is analyzed using phasors

Question 14

Give the general formula for te domain for current and then voltage

Answer 14

V(t) = Vsin (ωt+ θ)
I(t) = Isin (ωt+ Φ)

Question 15

Z formula and unit

Answer 15

Z= V/I
Impedance is directly proportional to voltage but inversely proportional to current

Unit ohms

Question 16

What is admittance
It’s unit and symbol

Answer 16

The reciprocal of impedance
Ie Y = 1/Z

Unit Siemens S
Symbol Y

Question 17

When were written in Cartesian form which is real and imaginary for Z

Answer 17

The resistance is real and reactance is imaginary

Question 18

For the Cartesian form of Z which part is always positive and which part can change and what happens SHEIN it changes

Answer 18

The real part is always positive ie resistance

The imaginary part can change
Whe positive it is inductive reactance and negative is capacitive reactance

Question 19

What is assigned to XL to account for the phase shift between current and voltage for an inductor 

Answer 19

j
ie JX subscript L

Question 20

What is assigned to XLcto account for the phase shift between current and voltage for an capacitor

Answer 20

-j
ie -jXc

Question 21

Total Impedance in series

Answer 21

Zeq=Z1 + Z2 + Z3
Like resistors in series

Question 22

Total Impedance in parallel

Answer 22

Like resistors in parallel

1/Zeq = 1/Z1 + 1/Z2 + 1/ Z3

Question 23

Two impedance in parallel

Answer 23

Like two resistors in parallel

Z1 × Z2 / Z1 + Z2

Question 24

Equal impedance in parallel

Answer 24

Like equal resistors in parallel

Value of on Z / number of Z

Question 26

In an phasor form what does V stand for

Answer 26

Rms value

Question 27

X subscript L

Answer 27

X sub L = jω L