| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.12 |
| Score | 0% | 62% |
Which of these materials is not a good conductor of electricity?
copper |
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gold |
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tin |
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air |
All conductors have resistance and the amount of resistance varies with the element. In general, metals make the best conductors of electricity and non-metals make the worst conductors of electricity.
Which of the following is the preferred method for splicing wires?
wrap in small gauge wire |
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soldering |
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wire crimps |
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screw-on connectors |
Splicing is permanently joining two wires together. Splicing can be done with screw-on connectors or wire crimps but the preferred method for splicing is soldering. Soldering takes the most effort but results in a connection that is electrically and mechanically identical to the original wire.
This circuit component symbol represents a(n):
capacitor |
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inductor |
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diode |
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transistor |
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.
A __________ electric current produces a magnetic field proportional to the amount of current flow.
moving |
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low voltage |
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high voltage |
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stationary |
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.
Inductance is a factor in which of the following?
an AC circuit |
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batteries connected in serial |
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a DC circuit |
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determining energy stored by a capacitor |
Inductance is a property of an AC circuit (or a component in an AC circuit) that quantifies resistance to changes in current. The current in an AC circuit is continuously changing and inductive reactance (the opposition to change) depends both on the inductance of the circuit or component and the rate at which the current is changing.