[D2L] Midterm

Question 1

What is Voltage?

Answer 1

A difference in charge between 2 points

Question 2

Common temporary magnets we use in HVAC are…

Answer 2

Contactors

Question 3

When all magnetic moments align, what is produced?

Answer 3

Magnetic Domain

Question 4

With the left hand rule, grabbing the conductor with your left hand what do your fingers wrapping around it represent?

Answer 4

Direction of magnetic force

Question 5

What is the basic principle of a transformer?

Answer 5

Mutual Induction

Question 6

How is self induction created?

Answer 6

EMF traveling in the opposite direction due to Impedance

Question 7

How many current paths are there in a series circuit?

Answer 7

one

Question 8

Thermocouples use heat to generate Electricity?

Answer 8

True

Question 9

What is static electricity?

Answer 9

the buildup of electrical charge in an isolated object

Question 10

How many electrons in a coulomb

Answer 10

6.28 x 10 exponent 18

Question 11

What is the symbol for electrical Charge?

Answer 11

Q

Question 12

If an atom gains free electrons it becomes a

Answer 12

Negative Ion

Question 13

When a car battery is dead

Answer 13

The charge is equalized

Question 14

What amount of current is enough to kill a person?

Answer 14

100 to 200 mA

Question 15

What is Applied voltage?

Answer 15

The Source voltage

Question 16

What is voltage drop?

Answer 16

a reduction in voltage due to an increase in current

Question 17

Which of the following is one way of stating Kirchhoff’s Voltage Law?

Answer 17

The algebraic sum of all voltages in a closed circuit is zero

Question 18

Switches are devices that consume electricity while performing an action

Answer 18

False, they are loads

Question 19

?What is Electromotive Force?

Answer 19

The energy used to move electrons away from atoms

Question 20

What is the purpose of a lockout system while working on electrical systems?

Answer 20

To prevent shocks and the accidental start-up of the equipment being serviced.

Question 21

What is electromagnetism?

Answer 21

The interaction of the forces that electric fields and magnetic fields create

Question 22

How is alternating current generated?

Answer 22

By spinning a coil of wire 120 times per second.

Question 23

When any force squeezes a crystals made from bone, wood, metal or minerals the material compresses and produces electricity, this is called…

Answer 23

Piezoelectricity

Question 24

Which of the following is NOT considered part of electrical PPE for the RACM trade?

a) class 0 insulated gloves
b) long sleeve polyester shirt
c) multimeter
d) safety glasses

Answer 24

long sleeve polyester shirt

Question 25

what is the FIRST thing that must be done if an electrical shock occurs?

Answer 25

remove the victim

Question 26

Kirchhoff's Current Law states that in an electrical circuit, the sum of the currents entering a junction must equal the sum of the currents leaving the junction T or F

Answer 26

True

Question 27

when illuminated, an incandescent light bulb will have a magnetic field close to the filament (glowing coil)?

Answer 27

True

Question 28

By winding a wire into a coil, an electromagnet with poles will be produced when current is passed through the wire?

Answer 28

True

Question 29

increasing the flow of current through a coil will..

Answer 29

increase the strength of the magnetic field

Question 30

the number of lines of magnetic flux may be increased by adding an iron core in the middle.

Answer 30

True

Question 31

A Megohmmeter (Megger) produces a _____ voltage output

Answer 31

High

Question 32

ferromagnetic materials, like iron, allow magnetic flux to pass through them easily because they have a high

Answer 32

permeability

Question 33

a material that does not allow easy passage of magnetic flux is said to have a high

Answer 33

reluctance

Question 34

the emf that is induced in a circuit by electromagnetism, is proportional to the rate of change of flux linkage. this statement could be used to summarize?

Answer 34

faraday's law

Question 35

if the direction of current flow is reversed through a coil, the resulting magnetic field will..?

Answer 35

reverse direction

Question 36

a DC transformer is widely used to convert a dangerous high voltage power source to a safer and more usable control voltage?

Answer 36

False, Transformer is always AC

Question 37

passing a conductor in parallel to lines of flux will induce a current of electromotive force? T or F

Answer 37

False

Question 38

an alternator converts....................., into........................ energy

Answer 38

mechanical, electrical

Question 39

in order to provide a useful low voltage control signal, a transformers primary and secondary coils should be in contact at each end of their conductors?

Answer 39

False, they should be isolated from each other