DC Final

Accurate troubleshooting of a parallel circuit cannot be performed with a voltmeter.

true

The total resistance of four resistors in parallel is always less than the smallest resistance.

true

A three-branch parallel circuit carries a total current of 1.2 mA. If I1 = 0.2 mA and I2 = 0.7 mA, then what is the value of I3?

0.3mA

A 250 μA current flowing through a 4.7 kΩ resistor produces a ________ voltage drop.

1.18 V

If three 75 W lamps are connected in parallel across a 125 V source, IT equals ________.

1.8A

Two 100 kΩ resistors are wired in series across a 20 V source. How much voltage does each resistor drop?

10 V

If 18 V and 6 V sources are connected in series opposing, what is the total voltage?

12 V

The total resistance of a three-branch parallel circuit is 76.92 Ω. If R1 = 100 Ω and R2 = 500 Ω, what is the value of R3?

140 Ohms

A 5.2 MΩ resistor, 1.2 MΩ resistor and 1 MΩ resistor are connected in parallel across a 15 V source. What is the total current if the 1.2 MΩ resistor opens?

2.41 uA

A two-branch parallel circuit contains these values: R1 = 1200 Ω, IT = 0.005 mA, I2 = 0.003 mA. What is the value of VR1?

2.4m V

If a 500 Ω, 1200 Ω and 10 kΩ resistor are connected in parallel across a 25 V source, how much current flows through the 1200 Ω resistor?

20.8mA

A 220 Ω 1/2 W resistor has burned open, so you look in your parts box to find a replacement. Although it is not good practice, which one of the following resistors could you use to repair the circuit?

220 Ω 1 W

When taking current measurements, it is extremely important not to accidentally place the meter across the voltage source.

True

The electrical symbol for voltage is ________.

V

Interpret the following mixed numbers and letters 3M3 on a resistor to the correct resistance of:

3300 Kilohms

If a 68 Ω, 33 Ω, 100 Ω and 47 Ω resistor are connected in series across a 9 V battery, the current equals ________.

36.3 mA

A 22 kΩ and 12 kΩ resistors are connected across a 68 V source. How is the voltage divided?

44 V and 24 V

A resistor with yellow, violet, orange and silver bands equals ________.

47 kΩ ± 10%

A resistor with yellow, violet, orange, and gold bands equals ________.

47 kΩ ± 5%

If the power dissipation in each of four parallel branches is 1 W, PT equals ________.

4W

If a 100 Ω, 220 Ω, and 330 Ω resistor are connected in series, total resistance equals ________.

650 Ω

If 5 A and 3 A enter a junction from two separate paths, how much current flows out of the junction?

8A

If twelve 1.5 MΩ resistors are connected in parallel across 50 V, RT equals ________.

0.125M ohms

In a three-resistor parallel circuit, R1 = 0.22 MΩ and R2 = 1 MΩ. If RT = 0.1166 MΩ, then what is the value of R3?

0.134M ohms

If 12 V and 17 V sources are wired in series aiding, what is the total supply voltage?

29 V

A resistor with orange, orange, red and gold bands has a value and tolerance of ________.

3.3 kΩ ±5%

If four 100 W lamps are connected in parallel across a 120 V source, what is the total current?

3.33A

A loaded voltage divider is a series-parallel circuit.

True

AC is often converted to DC with a power supply

True

Electromotive force is measured in volts.

True

Engineering notation is typically used in the expression of extremely large and small quantities in the electronics field.

True

If a 56 kΩ resistor carries 10 mA, it is safe to use a 10 W resistor.

True

If a circuit's resistance increases, its current decreases.

True

The current through any branch of a parallel circuit ________.

is inversely proportional to the branch resistance

If a 2.2 kΩ resistor and a 3.3 kΩ resistor are connected in parallel, RT equals ________.

less than 2.2k ohms

What type of resistor, used alone, could be used as a variable voltage-divider?

potentiometer

Which of the following is not a type of variable resistor?

potentiometer, thermistor photoconductive cell, they All are types of variable resistors.

Potentiometers and rheostats differ in that:

potentiometers utilize three terminals, while rheostats usually use only two terminals; potentiometers are used to vary voltages, while rheostats vary currents, and potentiometers utilize linear and nonlinear tapers, while rheostats usually utilize only linear tapers.

A(n) ________ is a material that has many free electrons.

Conductor

Voltage sources in series increase both voltage and current capacity.

False

According to Ohm's Law, if the voltage were to decrease while resistance remained the same, the current would

Decreases

Voltage and current are ________.

Directly Proportional

A Normally Open Push Button switch can carry current when not pushed.

False

A resistor color coded with yellow, violet and orange bands has a value of 4.7 kΩ.

False

Electrons have a positive charge.

False

If IR1 = 75 mA and IR2 = 12.7 mA in a two branch parallel circuit, IT = 85.7 mA.

False

If a circuit's resistance decreases, its current also decreases

False

If one branch of a parallel circuit opens, the total resistance decreases.

False

If the voltage applied to a circuit doubles, then power dissipation doubles

False

If three equal resistors are connected in parallel across 12 V, each resistor drops 4 V.

False

Maximum power is achieved when the load resistance is approximately two times the source resistance.

False

Negative charges move from the positive terminal to the negative terminal in an electrical circuit.

False

Power in a series-parallel resistor circuit is dissipated as:

Heat

Which is the correct formula for Ohm's Law?

I = V ÷ R

If voltage is 12 V and the resistance is color-coded brown-black-orange in Figure 3-1, what are the minimum and maximum possible currents?

IMINIMUM = 1 mA, IMAXIMUM = 1.5 mA

If the voltage is 15 V and resistance is color coded red-red-brown-silver in Figure 3-1, what are the maximum and minimum possible current?

IMINIMUM = 62.0 mA, IMAXIMUM = 75.8 mA

A formula that applies to a two-branch parallel circuit is ________.

IT = IR1 + IR2

As additional branch resistors are connected in a parallel circuit, ________.

IT increases and RT decreases

If one resistor opens in a parallel circuit, the total circuit resistance ________ and the total circuit current ________.

Increases, Decreases

Four resistors are connected in series across an 18 V source. Three resistors drop 0 V and one resistor drops 18 V. What's the trouble?

One resistor is open.

The symbol for electrical charge is ________.

Q

In solving series-parallel circuits using Ohm's law, first solve for:

RT

If the voltage across a circuit increases, ________.

The current Increases

A SPST switch is used to control one circuit.

True

If the current is constant, voltage and resistance are directly proportional.

True

If two resistors are in parallel, they drop the same voltage.

True

In a series circuit, the current is the same at every point in the circuit.

True

Kirchhoff's Voltage Law states that the algebraic sum of all the voltages around a closed path is zero

True

Resistance is the opposition to the flow of current.

True

The movement of free electrons through a conductor is called current.

True

The ohm is the basic unit of resistance.

True

The power rating for a resistor is mainly based on the physical size.

True

The total power dissipated by a parallel circuit can be found by adding the individual powers.

True

The total power dissipated in a series circuit equals the sum of the individual powers

True

Thevinizing a circuit creates an equivalent series circuit.

True

To measure the current through a resistor, place the ammeter so the current must pass through the meter.

True

Total power dissipated in a series circuit equals source voltage multiplied by current.

True

Two or more resistors connected in series form a circuit known as a voltage divider.

True

An analog meter has ________.

a needle and a scale to indicate the value

Every electrical circuit must contain ________.

a source, a load and a path

Any component that requires a source of power to function is called

an active component

Signals that vary continuously are called

analog signals

An ohmmeter should ________.

be placed across the resistor after the resistor has been disconnected from the circuit

To measure a circuit's source voltage, the voltmeter must ________.

be placed across the source

In order to measure the current in a circuit, an ammeter must ________.

be placed so the current must pass through the meter

A model of a complex electronic system is often simplified and represented as a

block diagram

If the current in a circuit equals 0 A, it is likely that the ________.

circuit is open

If one resistor opens in a parallel circuit, the total current ________.

decreases

In the American Wire Gauge sizes, as the numerical value of AWG goes higher, the cross-sectional area of the wire:

decreases.

If a 1/2 W resistor is used in the circuit in Figure 3-1, the current value ________.

depends upon the circuit's voltage and resistance

The ratio of the output of a circuit to the input is called

efficiency

The difference between electrical and electronic systems is

electrical deals with power while electronic deals with signals

The metric prefix μ (micro) is normally associated with ________ measurements.

extremely small

The difference between scientific and engineering notation is ________.

groupings of multiple of three digits, powers of ten representation, and single vs multiple digits before decimal point

If you want to measure a load voltage with a DVM, connect the meter ________.

in parallel with the load

On a resistor with numbers and letters, the position of the letter in the sequence represents:

the decimal point.

An insulator is a material with ________.

very few free electrons

What is the easiest, most practical measurement performed during troubleshooting?

voltage

If the measured circuit current is zero, it is likely that the ________.

voltage is turned off

Most DMMs will measure ________ ________ and

voltage, current, resistance