| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.38 |
| Score | 0% | 68% |
Which of the following is not a characteristic of a step-up transformer?
has more turns in the secondary winding than in the primary winding |
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increases voltage |
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the secondary voltage is higher than the primary voltage |
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the primary voltage is higher than the secondary voltage |
As their names indicate, a step-up transformer is used to step up or increase voltage and a step-down transformer is used to step down or decrease voltage. In a step-up transformer, the secondary voltage is higher than the primary voltage and it has more turns in the secondary winding than in the primary winding.
The ohm is a unit of measurement for:
resistance |
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capacitance |
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energy |
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power |
Resistance is opposition to the flow of current and is measured in ohms (Ω). One ohm is defined as the amount of resistance that will allow one ampere of current to flow if one volt of voltage is applied. As resistance increases, current decreases as resistance and current are inversely proportional.
This circuit component symbol represents a(n):
potentiometer |
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inductor |
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capacitor |
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resistor |
Resistors are used to limit voltage and/or current in a circuit and can have a fixed or variable resistance. Variable resistors (often called potentiometers or rheostats) are used when dynamic control over the voltage/current in a circuit is needed, for example, in a light dimmer or volume control.
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 maintain power in a circuit when the primary power source is disconnected |
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as a primary power source |
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to convert alternating current into direct current |
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.
The farad is a unit of measurement for:
energy |
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capacitance |
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inductance |
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power |
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.