| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.47 |
| Score | 0% | 69% |
Which of the following is a difference between a circuit breaker and a fuse?
a fuse responds more quickly than a circuit breaker |
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all of these |
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a circuit breaker can be reused |
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a fuse is cheaper than a circuit breaker |
Like fuses, circuit breakers stop current flow once it reaches a certain amount. They have the advantage of being reusable (fuses must be replaced when "blown") but respond more slowly to current surges and are more expensive than fuses.
Which of the following statements about electrical resistance is true?
the more resistive the conductor is the slower electron flow will be |
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the less resistive the conductor is the slower electron flow will be |
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the more resistive the conductor is the faster electron flow will be |
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electrically conductive materials have no resistive properties |
Resistance is opposition to the flow of current. As resistance increases, current decreases as resistance and current are inversely proportional.
A transistor works by allowing a small amount of current to control general current flow. Where is the small amount of current applied?
base |
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input |
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emitter |
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collector |
The transistor is the foundation of modern electronic devices. It is made entirely from semiconductor material (making it a solid state device) and can serve many different functions in a circuit including acting as a switch, amplifier, or current regulator. A transistor works by allowing a small amount of current applied at the base to control general current flow from collector to emitter through the transistor.
The conversion of alternating current (AC) into direct current (DC) is called:
inductance |
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reactance |
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rectification |
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capacitance |
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 capacitor is often used for which of the following purposes?
to allow a small amount of current to control a large amount of current |
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to convert alternating current into direct current |
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as a primary power source |
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to maintain power in a circuit when the primary power source is disconnected |
Capacitors store electricity and are used in circuits as temporary batteries. Capacitors are charged by DC current (AC current passes through a capacitor) and that stored charge can later be dissipated into the circuit as needed. Capacitors are often used to maintain power within a system when it is disconnected from its primary power source or to smooth out or filter voltage within a circuit.