| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.41 |
| Score | 0% | 68% |
Current is the rate of flow of electrons per unit time and is measured in:
ohms |
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coulombs |
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volts |
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amperes |
Current is the rate of flow of electrons per unit time and is measured in amperes (A). A coulomb (C) is the quantity of electricity conveyed in one second by a current of one ampere.
Which of the following is not a purpose of a resistor in an electrical circuit?
limit the current in the circuit |
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moderate the heat in the circuit |
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multiply the current in the circuit |
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control the voltage in the circuit |
Resistors can be chosen in a wide variety of values to control the voltage in a circuit, limit the current, or moderate the heat produced by the components in the circuit.
The voltage output of a transformer primarily depends on which of the following?
the diameter of the wire in the coils |
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the diameter of the coils |
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the number of turns in the wire of the coils |
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the conductor used for the wire in 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.
Which of the following statements about electrical resistance is true?
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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the more resistive the conductor is the slower 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.
This circuit component symbol represents a(n):
capacitor |
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transistor |
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inductor |
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diode |
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.