WorksheetsModule 3a Elec Fundamentals Revision
Total questions: 50
Worksheet time: 2hrs 39mins
A positive ion has:
gained an electron
lost an electron
has equal number of protons and electrons
A material that allows free flowing electrons to pass through it easily
insulator
conductor
resistor
Which is NOT a common semi-conductor material
silicon
germanium
boron
If a material is able to give up electrons more easily, it will be ________ on the triboelectric series.
Negative
Positive
Neutral
Contact, friction and ________ are causes of static electricity
Humidity
Separation
Rubbing
What is the distribution of static charges on an irregular shaped object?
accumulate at points, corners, etc.
accumulate at point of contact
spread evenly over material
Like charges _______
attract
repel
cancel out
An atom gains an electron. It is now what charge?
positive
negative
neutral
The Coulomb is approx how many electrons?
6.28 x 10^18
7.25 x 10^16
5.87 x 10^12
Coulombs Law states that "charged bodies attract or repel each other with a force that is __________ proportional to the individual charges, and ___________ proportional to the square of the distance between them".
inversely, directly
directly, inversely
Electricity moves through solids using
Free flowing electrons
Ions
Positive holes
In electron current flow the electricity flows from points of ______ potential to points of ______ potential
lower, higher
higher, lower
equal, different
Compressing quartz causes a small voltage to be produced. What happens when it is decompressed?
voltage goes away
voltage is reversed
electrons continue to flow in same direction
Heating a conductor to sufficient temperature to give off electrons is called
thermoelectric emmision
thermodynamic emission
thermionic emission
Select the equation that represents Ohms law
P = IV
R = VI
V = IR
Conductance (G) is measured in
siemans
ohms
volts
Which is NOT a factor that effects resistance of a wire
cross section
type of insulation
temperature
Which part of a thermocouple is the place where electrons start to move when the temperature is increased?
hot junction
cold junction
the power source
Which type of cell is rechargeable?
primary
secondary
tertiary
Connecting cells in series increases
voltage
current
capacitance
If you have 4 batteries (1.5V and 1A) connected in parallel, what will be the output?
6V and 1A
6V and 4A
1.5V and 4 A
Internal resistance in a battery...
opposes current and limits battery output
should be kept as high as possible
does not affect battery operation
Chromel alumel thermocouples are
J Type 850 deg
K Type 1200 deg
P Type 400 deg
The Seebeck Effect
generating potential via heat
generating potential via chemical reaction
generating potential via light
What is NOT part of a solar cell?
Cover Glass
P and N Type material
Anti-reflective coating
Electrolyte
A photo-electric cell is NOT also known as
solar cell
photovoltaic cell
light bucket
How much current flows in this circuit?
6 A
0.5 A
2 A
resistor: Brown Brown Red Gold
1K1 5%
1R1 5%
2K3 5%
What is the total circuit resistance?
16 Ohms
2 Ohms
10 Ohms
What is this electrical symbol?
Potentiometer
Rheostat
Resistor
In a balanced bridge:
R1 = 1k
R2 = 2k
R3 = 3k
R4 = ?
4k
6k
5k
Metal wound, wire wound and metal oxide are types of what?
Resistor
Capacitor
Generator
When is work done?
On weekdays
Whenever a force causes an object to move
When high power is available
If current is 2A and resistance is 1 Ohm, what is the power consumption?
4W
2W
3W
10 horsepower is equal to
7460 W
15 W
15kW
Capacitors _______ AC, ________ DC
pass, block
block, pass
Pick the factor that DOES NOT APPLY to capacitance
Area of plates
Temperature
Dielectric Material
Distance between plates
What does the grey strip down the side of an electrolytic capacitor represent?
negative leg
positive leg
size of capacitor
10 micro-farad capacitor and 10 Mega-ohm resistor are connected in series. Calculate the time it takes to fully charge the capacitor.
100 seconds
500 seconds
1 second
A capacitor will be charged 63.2 % after how many time constants?
1
5
The magnetism theory that describes tiny molecular magnets in a material?
Weber's Theory
Domain Therory
Ability of a material to act as the path for magnetic lines of force
Permeability
Coercive Force
Resistance
Circular induced currents caused by moving a conductor in a magnetic field
Counter EMF
Sparking
Eddy Currents
Magnets, copper wire and ____________ produce electricity
relative motion
electrons
commutation
All generators initially produce _______, but need a commutator to produce ______
AC, DC
DC, AC
electricity, an output
Name the red component
Commutator
Yoke
Armature
Pole
Interpoles in a generator are same polarity as the main pole
ahead of it
behind it
opposite it
Characteristic of a series motor
High torque
Constant Speed
Low Torque
Variable Speed
A compound motor combines the characteristics of what 2 motors together?
series and separately excited
parallel and shunt
series and shunt
What is NOT a way to reverse motor direction?
reverse the magnetism in the armature
reverse the magnetism in the field
reverse the current direction in both the armature and field
