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WorksheetsT3 PS - Electromagnetic Fields
Total questions: 21
Worksheet time: 1hrs 8mins
Refer to diagram
What is the name of the component that ensures that the coil rotates continuously in ONE DIRECTION.
Split ring
Communicator
DC generator
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In which direction will the coil rotate?
Clockwise
Anticlockwise
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What is the energy conversion which takes place while the motor is working?
Electrical energy to mechanical energy
Kinetic energy to electrical energy
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An AC generator, producing a maximum voltage of 320 V, is connected to a heater of resistance 35 Ω.
What is the structural difference between an AC generator and a DC generator?
DC generator: split ring and AC generator has slip rings
DC generator: commutator and AC generator has split rings
Refer to diagram
Calculate the rot mean square (rms) value of the voltage.
226,27 V
226,3 V
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Calculate the rot mean square (rms) value of the current in the heater.
6,46 A
6,5 A
Learners want to build a small DC motor as a project.
Choose three essential components that are needed for the building of the Motors.
Permanent magnets
Coils
Commutator (Split ring)
Slip ring
Jeff defines the term rms voltage as the voltage of AC is the potential difference which dissipates the same amount of energy as the equivalent DC potential difference.
Is this true or false?
(a)
An electrical device with a resistance of 11 Ω is connected to an AC source with an rms voltage of 240 V.
Calculate the maximum (peak) current passing through the device.
30,86 A
31 A
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What is the energy conversion that takes place during the operation of the DC generator.
Mechanical to electrical energy
Electrical to mechanical energy
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What is the total resistance of the circuit.
20,5 Ω
20 Ω
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Calculate the average power delivered to the device.
1,22 A
1,23 A
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Calculate the average power delivered to the device.
1,22 A
29,74 W
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What is the name of part R?
Armature
Brushes
Slip rings
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What is the name of part T?
Armature
Brushes
Slip rings
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What is the name of part X?
Armature
Brushes
Slip rings
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Give the NAME of the law upon which the operation of the generator is used.
(a)
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An AC supply is connected to a light bulb. The light bulb lights up with the same brightness as it does when connected to a 15 V battery.
What is the rms value of the potential difference of the AC supply?
15 V
45 V
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An AC supply is connected to a light bulb. The light bulb lights up with the same brightness as it does when connected to a 15 V battery.
If the resistance of the light bulb is 45 Ω, calculate the maximum current delivered to the light bulb.
0,47 A
0,5 A
Refer to diagram
What is the name of the component in this arrangement that makes it different from a DC generator.
Split rings
Slip rings
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A practical version of the generator above has a large number of turns of the coil and it produces an rms potential difference of 240 V.
The practical version of the generator above is connected across an appliance rated at 1 500 W.
Calculate the rms current passing through the appliance.
6,25 A
6,3 A
