ILT 106 Final Exam

A parallel circuit is composed of two branches with one 60 Ω resistor in each branch. What is the total resistance?

30 Ω

With the meter set on the 10 DCV scale what is the meter reading below?

Approximately 4.8 volts DC

With the meter set on the 100 DCMA scale what is the meter reading below?

Approximately 90 mA

What color used as the multiplier band means to divide the combined first two numbers by 10?

GOLD

To measure current in a circuit you must make your measurement:

In series with component to be measured

The Most Important Rule of Safety is:

TO THINK

The danger from an electric shock depends on which of the following: (This question will show a checkbox next to each answer, and the student must select ALL the answers you mark as correct)

The amount and type of current (AC or DC) Path Through the Body The person's overall health Duration: time exposed to current The amount of voltage present

An arc flash is simply an electrical short circuit through air.

True

In a parallel circuit, the voltage across each branch must be equal to supply voltage

True

A three-branch parallel circuit has a total resistance of 385.83 Ω. Resistor #1 equals 680 Ω resistor #2 equals 1500 Ω. What is the value of the third resistor?

2200 Ω

The only way to truly eliminate an arc flash hazard is to wear the proper PPE (Personal Protective Equipment) while working on the energized circuit.

False

What is indicated by the fourth color band on a four color band resistor?

tolerance

In a series circuit, the _______________ is the sum of the individual resistances.

total resistance

2 x10^E-6 is equal to

0.000002

If the current in a shocking incident approaches a value of _______________ ampere or more, the shock can be fatal.

0.1 or 100 milliamps

A series circuit has a total resistance of 180 Ω and an applied voltage of 120 V. What is the current flow?

0.667 A

An electrical circuit has a voltage of 50 V and a resistance of 5 Ω. What is the value of current?

10 A

A three-resistor circuit has a total power of 25 W. Two of the resistors dissipate 10 W and 5 W, respectively. How much power does the third resistor dissipate?

10 W

An electric circuit has a resistance of 20 Ω. The current is measured to be 6 A. How many volts are applied to the circuit?

120 V

A toaster is listed as 1560 W. When it is plugged into a 120 V circuit and starts to make toast, how many amperes will it draw?

13

Stay at least a minimum of _________ feet away from any high-voltage wires until the power has been turned off.

20 FEET

A series circuit has two resistors that dissipate 10 W and 15 W, respectively. What is the total power dissipation of the circuit?

25 W

A parallel circuit has a 10 Ω branch and a 22 Ω branch. The circuit has a supply voltage of 60 V. What is the current in the 10 Ω resistor?

6 A

An electric motor is running on 120 V. The current is measured to be 2 A. How many ohms of resistance is the motor?

60

A two-resistor series circuit has an applied voltage of 100 V. The voltage across one of the resistors is 40 V. What is the voltage across the other resistor?

60 V

A three branch parallel circuit has resistors of 27 Ω, 56 Ω, and 15 Ω. What is the total resistance?

8.23 Ω

What is the applied voltage in a series circuit with two resistors (25 V and 60 V, respectively)?

85 V

A series circuit has a total resistance of 240 Ω and a current flow of 4 A. What is the applied voltage?

960 V

To measure voltage in a circuit you must make your measurement

Across the component to be measured

When the approximate value of voltage or current being measured is not known:

Always start at the highest range setting on meter to avoid blowing a fuse

With the meter set to 30 volts DC what is the meter reading below?

Approximately 17 volts

The term "load" refers to the amount of _____ in a circuit branch.

CURRENT

The __________________________________ is the distance needed to limit unprotected skin to second-degree burns.

Flash Protection Boundary

The __________________________________ is the distance barriers are placed to protect unqualified personnel from entering this area unless escorted by a qualified person.

Limited Approach Boundary

The current, voltage, power, and resistance in a series circuit can be calculated using _____ law.

Ohm's

The __________________________________ is the distance only qualified personnel are allowed with protective clothing and PPE.

Restricted Approach Boundary

The amount of potential necessary to cause one coulomb to produce one joule of work is a(n) _____.

VOLT

What is another term for electromotive force (EMF)?

Voltage

One coulomb per second is equal to one _____.

ampere

In parallel circuits, the voltage drop across any branch is the same as the _____.

applied voltage

What force is demonstrated in objects with unlike charges?

attraction

A combination circuit is a circuit that contains _____.

both series and parallel components

A complete circuit is often referred to as a(n) _____ circuit.

closed

In series circuits, the _____ is the same at any point in the circuit.

current

When a circuit has only one path, the _____ is the same at any point.

current

Parallel circuits are also referred to as _____.

current dividers

A voltage _____ is used to provide different voltages between certain points in a circuit.

divider

What is the maximum number of valence electrons in an atom?

eight

What part of an atom has a negative charge?

electron

Electrical current is the flow of _____.

electrons

In a series circuit, the sum of the voltage drops is _____ the applied voltage.

equal to

What device is designed to open and disconnect a circuit in the event of excessive current?

fuse

The metric prefix associated with 10 raised to the 9 power is:

giga

The metric prefix associated with 10 raised to the 3 power is:

kilo

In a parallel circuit, the total resistance is _____ branch resistor value.

less than the lowest

The metric prefix associated with 10 raised to the 6 power is:

mega

The metric prefix associated with 10 raised to the negative 6 power is:

micro

The metric prefix associated with 10 raised to the negative 9 power is:

nano

What part of an atom has no charge?

neutron

The nucleus of an atom contains _____.

neutrons and protons

The unit of resistance to current flow is the _____.

ohm

A series circuit has _____ path(s) for current flow.

one

With the meter set to measure resistance the meter reading below is reading a(n)?

open

The valence shell of an atom is the _____ shell.

outer

Circuits that have more than one path for current flow are _____ circuits.

parallel

The metric prefix associated with 10 raised to the negative 12 power is:

pico

By observing the direction of current flow through the circuit, voltage _____ can be determined.

polarity

A method for finding total resistance of parallel resistors is _____.

product over sum reciprocal formula resistors of equal value

A circuit that has only one path for current flow is a _____ circuit.

series

An insulator is an element containing _____ valence electrons in the outer shell of its atom.

seven or eight

There is very little resistance and a large amount of current flows in a(n) _____ circuit.

short

In a parallel circuit, the total current flow is equal to the _____ of the currents through all the branches.

sum

The metric prefix associated with 10 raised to the 12 power is:

tera

The _____ of a resistor indicates the plus and minus limits of a resistor's ohmic value.

tolerance

The danger of severe electric shock decreases with which of the following:

using appropriate PPE (Personal Protective Equipment)

A resistor whose values can be varied over a range of values is called a _____ resistor.

variable

What force pushes the electrons through a resistance in a circuit?

voltage

The amount of _____ across a resistor is proportional to its resistance.

voltage drop

The amount of electrical power being used in a circuit is measured in ____.

watts

2k-volts is equal to how many Mega-volts.

0.002M-volts

If a series circuit has resistor values of 27 Ω, 56 Ω, and 82 Ω, the total resistance is _______________ Ω.

165

Power cords should always be checked before use. If the insulation is cracked or cut, the cord can be used as long as it is properly repaired after use.

False

The total Current in a parallel circuit is equal to the sum of the currents through all of the circuit branches.

True

What standard prefix in engineering notation indicates multiplication by 1,000,000,000?

giga (G)

The metric prefix associated with 10 raised to the negative 3 power is:

milli

Conventional current flow theory states that current flows from the most _______________.

positive point to the most negative

A variable resistor with three terminals is called a _____.

potentiometer

What is another term for a variable resistor?

potentiometer

What part of an atom has a positive charge?

proton

An interlock switch that cuts the power off equipment is also known as a safety switch.

True

A conductor is made from an element that contains between _____ electrons in the outer shell of its atom.

one and three

What type of resistors are generally used when a high power rating is needed?

wire-wound

The statement, "In a DC circuit, the current is directly proportional to voltage and inversely proportional to resistance," is know as _____ law.

Ohm's

Arc flash risk assessments determine the arc flash boundaries and the (PPE) Personal Protective Equipment that must be used when approaching each boundary.

True

It is not permissible to move or touch a person receiving an electrical shock if they are still in contact with the source of electricity.

True

The ohm value of a carbon composite resistor can be determined by the "color code."

True

What are the three principle parts of an atom?

electron, neutron, and proton

Adhering to the practice of always disconnecting or turning supply source off before changing range on meter will result

longer meter life better relaibility of meter less fuse blowing

What is the most common method of producing electricity?

magnetism

Solving combination circuits (series-parallel) includes steps in which you _____.

reduce the circuit to a simpler circuit

A basic law of physics states that like charges _____ and opposite charges _____.

repel; attract

What force is demonstrated in objects with like charges?

repulsion

A variable resistor with two terminals is called a _____.

rheostat

How many color bands are used on resistors that have a tolerance of ±20 percent?

three

TRUE or FALSE: When zeroing meter before making resistance measurements you should always make sure you can see a reflection of the meter's needle in the mirror on the face of the meter

False

Temperatures during an arc flash event may exceed a temperature of 350,000 degrees F. approximately four times the surface temperature of the sun.

False

The amount of current flowing in a series circuit through each resistor is directly proportional to individual resistance values.

False

Most devices such as light receptacles in homes and office buildings are connected in parallel circuits.

True

If a circuit is open, current _____ flow.

will not

Avoid having liquids such as water, coffee, or soda at your workstation or around electrical equipment or machinery in general. Liquids are excellent conductors of electricity and therefore increase the risk of electric shock.

True

Never work on an energized circuit if power can be disconnected.

True

Work with one hand when possible: Electric shock can be fatal when traveling from hand to hand because the current path can be through the heart.

True