CH 2_BOOK_BASIC LAWS

Question 1

Does a resistor obey Ohm’s law?

Answer 1

Yes: A resistor is a passive element in which the voltage v across it is DIRECTLY PROPORTIONAL to the current i through it.

Question 2

What is the formula for Ohm’s law?

Answer 2

v = iR

Question 3

Is a short circuit a resistor?

Answer 3

Yes, with ZERO resistance.

Question 4

Is an open circuit a resistor?

Answer 4

Yes, with INFINITE resistance.

Question 5

What is the formula for CONDUCTANCE?

Answer 5

Question 6

The CONDUCTANCE of a resistor is the ____ of its resistance?

Answer 6

Reciprocal

Question 7

What is a branch?

Answer 7

A single two-terminal element in an electric circuit (such as a voltage source or resistor).

Question 8

What is a node?

Answer 8

The point of connection between 2 or more branches.

Question 9

What is a loop?

Answer 9

A closed path in a circuit.

Question 10

A network with (b) branches, (n) nodes, and (l) independent loops will satisfy the fundamental theorem of network topology. What is this formula?

Answer 10

Question 11

Kirchhoff’s Current Law (KCL) states that currents at any node algebraically sum to ____?

Answer 11

Zero

(N) Number of branches connected to the node
(i_n) nth current entering (or leaving) the node.

Question 12

The sum of currents entering a node equals?

Answer 12

The sum of currents leaving the node.

Question 13

Kirschhoff’s Voltage Law (KVL) states that the voltages around a closed path algebraically sum to ____?

Answer 13

Zero

(M) Number of voltages/branches in the loop
(V_m) The mth voltage

Question 14

Two or more elements are in series if?

Answer 14

• Share a single node (that is not shared by other elements)
• Carry the same current

Question 15

When elements are in series, is the current that flows through them the same or different?

Answer 15

The same (i_1 = i_2)

(But not the same voltage)

Question 16

When are two or more elements in parallel?

Answer 16

• Connected to the same two nodes
• Same voltage across them

Question 17

Do elements in parallel have the same voltage or current?

Answer 17

Same voltage, different current.

Question 18

When two resistors are in SERIES, what are the formulas for their Equivalent Resistance (R_eq) and Equivalent Conductance (G_eq) ?

Answer 18

Question 19

When two resistors are in PARALLEL, what are the formulas for their Equivalent Resistance (R_eq) and Equivalent Conductance (G_eq) ?

Answer 19

Question 20

The VOLTAGE division principle for two resistors in SERIES is:

Answer 20

Question 21

The CURRENT division principle for two resistors in PARALLEL is:

Answer 21

Question 22

The formulas for a delta-to-wye transformation are:

Answer 22

Question 23

The formulas for a wye-to-delta transformation are:

Answer 23

Question 24

What is resistance?

Answer 24

Ability to resist current.

Question 25

What is the formula for resistance?

Answer 25

p = Resistivity of material l = Length A = Cross-sectional area

Question 26

VIEW ONLY: Resistivities of common materials.

Answer 26

Question 27

Ohm's Law states that the voltage (v) across a resistor is ____ ____ to the current (i) flowing through the resistor.

Answer 27

Directly proportional

Question 28

Refer to the formula for resistance (R) and rewrite it in terms of their units.

Answer 28

Question 29

The direction of current (i) and polarity of voltage (v) must conform with the ____ sign convention.

Answer 29

Passive.

Question 30

When v=iR, how does current flow?

Answer 30

Current flows from a higher potential to a lower potential.

Question 31

When v=-iR, how does current flow?

Answer 31

Current flows from a lower potential to higher potential.

Question 32

The value of Resistance can range from ____ to ____?

Answer 32

Zero to infinity.

Question 33

A common variable resistor is also known as a?

Answer 33

Potentiometer

Question 34

What are the 2 common types of resistors?

Answer 34

a) Wirewound b) Carbon film

Question 35

What are the circuit symbols for a) A variable resistor in general b) A potentiometer

Answer 35

Question 36

What are the 2 types of variable resistors?

Answer 36

1) Composition 2) Slider pot

Question 37

Do all resistors obey Ohm's law?

Answer 37

No.

Question 38

A resistor that obeys Ohm's Law is known as a ____ resistor.

Answer 38

Linear

Question 39

What makes a resistor LINEAR?

Answer 39

It has a constant resistance.

Question 40

What makes a resistor NON-LINEAR?

Answer 40

Its resistance varies with current

Question 41

What is CONDUCTANCE? What is its SI unit?

Answer 41

Conductance is the ability of an element to conduct electric current; it is measured in mhos (℧) or siemens (S).

Question 42

From the formula for conductance, what is the formula for current?

Answer 42

Question 43

What is the formula for power in terms of resistance (R)?

Answer 43

Question 44

What is the formula for power in terms of conductance (G)?

Answer 44

Question 45

The POWER dissipated in a resistor is a linear or non-linear function of either current or voltage?

Answer 45

Non-linear

Question 46

Since R and G are positive quantities, the power dissipated in a resistor is always positive. Thus, a resistor always ____ power from the circuit. This confirms the idea that a resistor is a ____ element, incapable of generating energy.

Answer 46

Absorbs, passive

Question 47

A loop is said to be ____ if it contains at least one branch which is not a part of any other ____ loop.

Answer 47

Independent, independent

Question 48

Referring to this illustration, rearrange the terms to show the currents entering and leaving the node.

Answer 48

Question 49

VIEW ONLY: Parallel circuit KCL

Answer 49

Question 50

Two circuits (or circuits in general) are said to be equivalent if they have the same ____________?

Answer 50

i-v relationship at a pair of terminals.

Question 51

In this example, use KVL to get an equation of the voltages around the loop. Rearrange the terms to follow the formula: Sum of voltage drops = sum of voltage rises

Answer 51

Question 52

What are the voltage and current formulas for resistors in series?

Answer 52

Voltage can also be written as v = iR_eq

Question 53

The ____ ____ of any number of resistors connected in series is the sum of the individual resistors.

Answer 53

Equivalent resistance

Question 54

Resistors in SERIES behave as:

Answer 54

A single resistor whose resistance is equal to the sum of the resistances of the individual resistors.

Question 55

To determine the voltage across each resistor in series, we use which formula?

Answer 55

Question 56

Referring to the Principle of Voltage, if a voltage divider has N resistors (R_1, R_2,..., R_N) in series with the source voltage (v), the nth resistor will have a voltage drop of: (Provide formula)

Answer 56

Question 57

In an example of two resistors in parallel, observe the formulas derived for voltage and current. What formula do we get for current in terms of voltage and equivalent resistance?

Answer 57

Question 58

From this formula for equivalent resistance for resistors in parallel, what formula can we derive for equivalent resistance?

Answer 58

Question 59

The Equivalent Resistance of two parallel resistors is equal to ________________?

Answer 59

The product of their resistances divided by their sum.

Question 60

VIEW ONLY: Equivalent Resistance in parallel circuit

Answer 60

Question 61

In parallel, R_eq is always smaller/bigger than the resistance of the smallest resistor in the circuit?

Answer 61

Smaller

Question 62

Conductances in parallel behave as ?

Answer 62

A single conductance whose value is equal to the sum of the individual conductances.

Question 63

The ____ ____ of resistors connected in parallel is the sum of their individual conductances. What is the formula for G_eq?

Answer 63

Question 64

What is the formula for the equivalent conductance G_eq of N resistors in series?

Answer 64

Question 65

VIEW ONLY: Current Divider (series)

Answer 65

Question 66

STILL MISSING WYE-DELTA INFO