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13 Cards in this Set
- Front
- Back
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What are the 2 main functions of a resistor? |
1. To divide voltage -or- 2. To limit the flow of current in a circuit |
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What is significant about the value of a fixed resistor? |
Its has 1 ohmic value that cannot be changed |
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State 3 types of fixed resistors: |
1. Composite carbon 2. Metal film 3. Wire-wound |
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What are 2 ways carbon resistors change their resistance? |
1. Age 2. Overheated |
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How does a metal film resistor change its resistance compared to a carbon resistor? |
Metal film resistors never change their resistance, but are more expensive than carbon resistors |
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What is the main advantage of wire-wound resistors? |
High-power ratings |
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What do the bands of color on a resistor indicate? |
Resistance value and tolerance |
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What is a potentiometer? |
A variable resistor used as a voltage divider |
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What is significant about a variable resistor? |
They can change their value within the limit of their full value. |
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How should a tubular wire-wound resistor be mounted and why? |
Vertically; produces an airflow "chimney" effect that keeps the resistor from overheating |
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What is a rheostat? |
A variable resistor that has 2 terminals |
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What is significant about potentiometers? |
They can be used as a rheostat by using only 2 of its 3 terminals. |
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What is a common name for a variable resistor? |
Pot |
