WorksheetsDC Theory Level 1
Total questions: 26
Worksheet time: 1hrs 1mins
The accepted theory states that a ________ ________ _______ holds the nucleus of an atom together.
magnetic centrifugal force
polarized magnetic force
strong nuclear force
electrical magnetic force
In the nucleus, the _______ and ______ are found at the center of an atom.
proton and neutron
quark and isotope
negative and positive
valence and ring
Thermoelectricity is the production of energy using ______.
light
pressure
chemicals
heat
How many electrons are contained in the valence shell (outer) of a copper atom?
29
none
1
2
Which of the following methods cannot be used to produce electrical current.
1. Chemical Action
2. Heat
3. Pressure
4. Light
5. Magnetic Fields
Magnetic Fields
Pressure
Light
None of them, they are all methods
The piezoelectric effect is electricity produced by what?
chemical reaction
pressure
magnetic field
ion transfer
A battery is made up of _________ cells.
one or more
always one
never more than one
always multiple
Primary cell batteries are rechargeable.
True
False
Secondary battery cells are rechargeable.
True
False
Battery cells connected in series produce less voltage.
True
False
Depending on the position of a switch a circuit can be open or closed.
True
False
A switch in the open position creates an _____ circuit.
closed
energized
parallel
Open
The number of ________ in a switch refers to the number of different actions (closed positions) of a single circuit within a switch.
throws
poles
options
terminals
In a simple DC circuit, if there is no current flow, the circuit is said to be _______.
closed
open
series
parallel
A kilo-watt hour is a measurement of how much power is used in respect to ________.
voltage
current
time
resistance
Power cannot exist without some form of _________ __________.
magnetic induction
energy conversion
current flow
closed circuit
250 kilohms divided by 10 equals _____.
2500 kilohms
1 kilohm
25 kilohms
25000 kilohms
How much power is consumed in a 600 ohm load drawing 0.20 amps?
24 watts
240 watts
120 watts
48 watts
The resistance of a conductor is inversely proportional to its _____________________.
length
current flow
voltage drop
cross sectional area
I2R loss is defined as what?
unwanted heat loss in conductors
increase in heat from friction
current leakage
magnetic induction
Using the following formulas:
Area=D Squared or Area=D2 and
R=KxL/A
Calculate the resistance of a piece of copper wire with a diameter of 120 mils and a length of 2 miles. Given: Copper=10.4 K
172 ohms
7.63 ohms
14.2 ohms
2304.2 ohms
Using the following formula:
Evd=IxKx2L/Acmil
What is the percentage voltage drop on a 208 volt circuit with 12AWG (6530 cmil) copper wire supplying a 14 amp resistive load 300 feet away?
Given: Kcopper=10.4
4.24%
12.33%
8.46%
6.43%
A resistor with left to right color code bands of red, black, orange and silver could have an acceptable resistance as low as _________.
18,000
18,000
18,000
All of the above
Three of the following items are correct for a force that may be produced by electricity.
Which one is incorrect?
Jacob Sams
heat
light
power
Electron theory of current flow states that current in a circuit flows from negative to positive.
True
False
Using the following formula:
A=IxKx2L/Ex3%
What size copper wire (in circular mils) would be needed to meet the minimum voltage drop requirements for a 120 volt circuit supplying a 20 milli amp load 400 feet from the source? Given:Kcopper=10.4
94.22 cmil
189.84 cmil
12.34 cmil
46.22 cmil
