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WorksheetsElectrical Science 202 1\6
Total questions: 50
Worksheet time: 7hrs 14mins
What is the smallest part of any material called?
Atom
Molecule
Quark
Dark Matter
What are the two main parts of an atom called?
Nucleus and Proton
Electron and Nucleus
Proton and Electron
Electron and Positron
An electrically neutral atom has:
more electrons than protons
more protons than electrons
as many protons as there are electrons
an uneven number of protons and electrons
A positively charged atom will:
attract a nearby electron
become electrically neutral
repel electrons
cease to exist
What does EMF stand for?
Extendedmechanical Force
Electrostatic Force
Electromechanical force
Electromotive Force
What is the flow of electrons around a circuit called?
A voltage
An electric current
An electrical resistance
An electrical charge
In order for electrons to flow, a circuit must:
have an open circuit switch
be complete with no breaks
have no voltage source
have a lamp fitted in the circuit
The charge state of a proton and electron are
positive and negative respectively
negative and positive respectively
both positive
both negative
A conductor is a material that:
will not allow the flow of current
will not allow the movement of electrons
has protons that can easily be dislodged
has loosely attached electrons that can easily be dislodged
Which of the following materials are electrical conductors
oil, sea water and steel
iron, lemon juice and dirty water
mercury, platinum and porcelain
plastic, concrete and gold
Which of the following materials are electrical insulators
lemon juice, dry paper and dry wood
bronze, silver and aluminium
concrete, brass and fibreglass
glass, rubber and ceramic
What are the three effects of an electric current
electrostatic, resistive and passive
Thermal, chemical and magnetic
Chemical, magnetic and acoustic
Thermal, solar and heat
What is the SI unit of length?
Joule
Metre
Farad
Ohm
What is the SI unit of time?
Watt
Hertz
Ohm
Second
What is the SI unit of velocity
Volt
Metres/second
Ampere
Henry
What is the SI unit of mass?
Square metre
Metre
Kilogram
Cubic metre
What is the SI unit of resistivity?
Joule
Rho
Ohm
Watt
What is conventional current flow?
Electrons that flow from positive to negative
Electrons that flow from negative to positive
Electrons that have no flow and remain static
Electrons that will only flow in a non conductive material
Identify the correct formula for Ohms law
V = IR
P = IR
I = V2/R
W = I2R
A circuit with a 10V source across a 5 ohm resistor will have a current flow of
5A
2.5A
2A
50A
The I, V and R letters in the Ohms Law formula stand for:
Voltage, Capacitance and current
Wattage, Voltage and Current
Current, Voltage and Resistivity
Current, Voltage and Resistance
When transposing a formula, you must:
Do the same to both sides of the equation
Multiply one side and divide the other side of the equation
It doesn't matter what you do to either or both sides of the equation
Always subtract the subject of the formula you are trying to find
What is 10mA as an ordinary number
0.01
0.001
0.0001
0.00001
What is 0.0000025 expressed in engineering notation
2.5 x 10-3
0.25 x 10-6
2.5 x 10-6
25 x 10-6
What is the result of (5 x 10-3) + (5000 x 10-6) as an ordinary number
50.0
0.1
0.01
0.05
A right angled triangle has two shorter sides of lengths 5cm and 8cm.
What is the length of the hypotenuse?
10.01cm
7.98cm
9.43cm
8.22cm
When using trigonometry to find angles and lengths of sides, what are the three sides commonly labelled as?
Hypotenuse, Adjacent and opposite
Adjacent, Hypotenuse and other
Opposite, Adjacent and Hyperbola
Hypotenuse, Active and Opposite
Identify the correct formula for Pythagoras
c2 = b2 + a2
c2 = a + b
c = a2 + b2
c = b + a
Five voltages are measured as follows: 2v, 3v, 3.5v, 4v and 6v.
What is the mean voltage?
2.9
3.0
3.7
3.9
What is the resistance of a circuit whose source voltage is 12v and the current flowing is 0.1A
100Ω
115Ω
110Ω
120Ω
Two 50Ω resistors are connected in parallel. What is the total resistance?
100Ω
25Ω
16.66Ω
75Ω
A circuit consisting of three resistors in series has a total resistance of 70Ω.
R1 = 30Ω, R2 = 35Ω. What is the value of the third resistor?
10Ω
20Ω
15Ω
5Ω
A circuit consists of a 10Ω resistor with 50V across it.
What is the current flowing in the circuit?
4A
7A
5A
6A
Two resistors, 12Ω and 8Ω are connected in series and have 100V across them.
How much current is flowing around the circuit
4A
4.5A
6.5A
5A
What is the total circuit resistance when a 30Ω and a 50Ω resistor are connected in parallel?
18.0
18.25
18.75
19.0
What is the total circuit resistance when a 20Ω, 40Ω and a 60Ω resistor are connected in parallel?
10.85Ω
10.90Ω
10.95Ω
10.98Ω
Two resistors are connected in series, each having a value of 100Ω. If a voltage of 70V is connected across them, what will be the voltage drop across each resistor?
50V
35V
25V
100V
Three 10Ω resistors are connected in parallel. If the total circuit current flowing is 12A, what is the current flowing in each branch?
3A
3.5A
4.0A
4.5A
If a 2Ω resistor has a current of 10A flowing through it , how much power will be dissapated in the resistor?
100W
200W
300W
400W
Three resistors of values, 20Ω, 30Ω and 50Ω are connected in series. and a 200V supply is connected across them. What will be the voltage drop across the 30Ω resistor?
40V
60V
100V
200V
Which of the following would be a correct formula for resistance in parallel?
Rt = 1/R1 + 1/R2 + 1/R3
Rt/1 = 1/R1 + 1/R2 +1/R3
1/Rt = 1/R1 + 1/R2 +1/R3
1/Rt = R1 + R2 + R3
Kirchhoff's current law states:
The sum of the currents leaving a point is dependant on the voltage of the circuit
The sum of the currents arriving at a point must equal the sum of currents leaving that point
The sum of currents arriving at a point will leave that point depending on the resistance
The sum of currents arriving and leaving a point will always be different
Which of the following are correct formulas for calculating power?
P = VI
P = RI
P = I2R
P = V2/R
What is the power loss in a cable of 0.30Ω when a current of 40A is flowing
380W
390W
480W
520W
An appliance is rated at 3kW, 230V. What is the current drawn from the supply
13.01A
13.04A
13.07A
13.09A
What is the rating of a 3kΩ resistor in watts if it has to be capable of carrying a current of 500mA.
7.50W
75.0W
750W
7500W
What is 17.2 x 10-9 expressed as an ordinary number
0.00000172
0.000000172
0.0000000172
0.0000000017
What is 2/3 + 4/6 Check all answers - could be more than one!
4/3
2/3
1 1/3
1/3
Kirchhoff's voltage law states that the sum of what should be equal to the supply voltage
The circuit resistances
The Branch currents
The total power dissaped in the circuit
The voltage drops across each component
Ohms law is a relationship between:
Voltage, power and resistance
Resistance, power and current
Voltage, current and resistance.
Current, voltage and power
