WorksheetsPrinciples of Science Mock Paper 2
Total questions: 36
Worksheet time: 39mins
From a 50 metre cable drum, you have installed 13.6 metres of cable.
What percentage of cable has been used?
3.8%
72.8%
27.2%
65%
An insulation resistance tester is used to record the following values:
55MΩ, 72MΩ, 55MΩ, 18.5Ω, 10 MΩ and 89MΩ. What is the mean of
these values?
49.9MΩ
89MΩ
55MΩ
18.5MΩ
The SI unit for resistivity is?
a) Ohm
M
R
Ωm
Potential Difference is measured in?
Amps
Volts
Joules
Newton's
In the SI system, time is measured in?
(a)
1) Lifting a load an electric motor uses 180,000 Joules of energy in 1 ½ minutes.
What is the power rating of the motor?
Answer in Watts amount.
Crowbars are an example of what type of lever?
Class 1
Class 2
Class 3
Class 4
Force on a load is considered to be a combination of:
energy and work done
weight and energy
time and acceleration
Mass and Gravity
1) An electric motor has a 1.8 kW input and an efficiency of 88%.
What is the motor’s output?
Answer is required to be in Kw
A four pulley system is required to lift a load force of 20000 Newton’s.
What is the effort force required to lift this load?
a
5000N
800000N
5000 Kg
10000 N
A set of gears has a ratio of 16:1. The smaller cogwheel has 9 teeth.
How many teeth does the larger cogwheel have?
14
41
82
144
Current is described as:
the pressure to move the charge within a circuit.
the movement of electrons within a closed circuit.
the movement of protons within a conductor.
the standing force of the neutrons within an open circuit.
Porcelain is best described as?
A good conductor of electricity
A semi-conductor of electricity
An unstable conductor of electricity
A good insulator of electricity
A 2.5mm2 copper conductor has a resistance of 1.5 Ohms.
If the conductor’s length is doubled what would the resulting resistance be?
6 Ohms
1.5 Ohms
3 Ohms
0.3 Ohms
A copper conductor has a resistance of 0.62 Ohms and is 36 meters long.
What size is the conductor? Take the resistivity of copper to be 0.0172µΩm.
1 mm2
1.5 mm2
2.5 mm2
4 mm2
Two 4mm2 copper conductors are connected in parallel.
Each conductor has a resistance of 0.5 Ohms. What is the combined resistance of the two conductors?
0.5 Ohms
0.25 Ohms
1 Ohm
0.75 Ohm
A 5 Ohm resistor and a 7 Ohm resistor are wired in series and connected to a 25 volt supply. What is the power dissipated in the 7 Ohm resistor?
52 Watts
57 Watts
89 Watts
30 Watts
A copper conductor is forty meters long and has a c.s.a of 6mm2. If the conductor material was changed to aluminium the resulting resistance would be:
The same
Lower
Higher
Unstable
Which statement is correct with regards to what makes a good insulator?
The electrons are tightly bound to the nucleus.
The electrons are loosely bound to the nucleus.
The protons are tightly bound to the nucleus.
The protons are loosely bound to the nucleus.
Organize these options into the right categories
Oil
Gold
Silver
Plastic
Rubber
Aluminium
Which effect would make a Fuse blow?
Chemical
Magnetic
Thermal
Solar
What is the total combined resistance of the resistors show in the figure above?
What is the missing voltage value in the figure?
25 Volts
12.5 Volts
50.5 Volts
27.5 Volts
A 16 Amp motor is connected to a cable with a very high resistance.
Which of the following issues would occur?
The motor will pull more current than it is designed to pull and damage itself.
Too much voltage will appear at the motor terminals damaging the motor.
There will be not enough voltage to operate the motor
The motor would run in reverse.
An aluminium conductor has a resistance of 0.88 Ohm’s and a c.s.a of 1.5mm2.
How long is the conductor if it’s resistivity is 2.84x10-8 Ωm?
46.5 m
23 m
34.5 m
62 m
Magnetic Flux Density is defined by:
the measurement of quantity of magnetic flux.
the amount of flux in a given area.
the strength of the magnet
the magnets north and south poles.
15) A electric motor has a magnetic flux density of 30 Tesla’s which covers an area of 250mm2.
What is the motor’s magnetic flux value?
75 Wb
750 Wb
7.5 mWb
a) 7.5µWb
To induce an EMF into a conductor, what must you do?
Wrap the conductor around a magnet
Place and hold still a closed conductor within a magnetic field
Attach a magnet onto a conductor
Pass a closed conductor through a magnetic field
Identify the slip rings in the picture?
B
A
C
D
Identify from the figure the Period?
A
B
C
D
The formula to calculate the induced EMF within a conductor is:
E=VIL
E=BIL
E=VBI
E=WbIL
How long would a conductor need to be to produce 12 Volts
when passed through a 0.9 Tesla magnet at 4m/s?
33 m
3.3 m
33 cm
33 mm
Which device is used to change alternating current into direct current?
Inverter
Pacifier
Converter
Rectifier
In which of the following equipment would you expect to find a light dependant resistor?
Smoke Detector
Rectifier
Solar Sensor
Dimmer Switch
Identify the device in the picture?
Triac
Thermistor
Resistor
Inverter
Identify the device in the picture?
Triac
Diac
Resistor
Diode
