| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.40 |
| Score | 0% | 68% |
What is the primary difference between a rectifier and an inverter?
a rectifier strips out the AC portion of electricity while an inverter strips out the DC portion |
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a rectifier converts an AC input to DC while an inverter converts a DC input to AC |
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a rectifier strips out the DC portion of electricity while an inverter strips out the AC portion |
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a rectifier converts a DC input to AC while an inverter converts an AC input to DC |
A diode allows current to pass easily in one direction and blocks current in the other direction. Diodes are commonly used for rectification which is the conversion of alternating current (AC) into direct current (DC). Because a diode only allows current flow in one direction, it will pass either the upper or lower half of AC waves (half-wave rectification) creating pulsating DC. Multiple diodes can be connected together to utilize both halves of the AC signal in full-wave rectification.
Which of the following will increase the magnetic field produced by the electric current in a wire?
construct the wire from conductive material |
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construct the wire from insulative material |
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wind the wire into a coil |
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wrap the wire around a ceramic core |
A moving electric current produces a magnetic field proportional to the amount of current flow. This magnetic field can be made stronger by winding the wire into a coil and further enhanced if done around an iron containing (ferrous) core.
Why does current in an electric circuit create heat?
current is naturally hot |
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heat is created when the current overcomes resistance in the wire |
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the wire in the circuit burns when current passes through |
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voltage is naturally hot |
Current in an electric circuit creates heat when the current overcomes resistance in the wire.
The voltage output of a transformer primarily depends on which of the following?
the conductor used for the wire in the coils |
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the number of turns in the wire of the coils |
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the diameter of the wire in the coils |
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the diameter of the coils |
A transformer utilizes an inductor to increase or decrease the voltage in a circuit. AC flowing in a coil wrapped around an iron core magnetizes the core causing it to produce a magnetic field. This magnetic field generates a voltage in a nearby coil of wire and, depending on the number of turns in the wire of the primary (source) and secondary coils and their proximity, voltage is induced in the secondary coil.
The formula specifying Ohm's law is which of the following?
V = I2R |
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\(V = {I \over R}\) |
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\(V = {R \over I}\) |
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V = IR |
Ohm's law specifies the relationship between voltage (V), current (I), and resistance (R) in an electrical circuit: V = IR.