| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.68 |
| Score | 0% | 74% |
You would measure the amount of voltage between two points in a circuit with a(n):
ammeter |
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battery |
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voltmeter |
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reostat |
Voltage (V) is the electrical potential difference between two points. A voltmeter is used to measure the voltage between two points in a circuit.
The valence shell of a semiconductor is how full of electrons?
less than half full |
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empty |
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half full |
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more than half full |
Semiconductors have valence shells that are exacly half full and can conduct electricity under some conditions but not others. This property makes them useful for the control of electrical current.
A transistor to an electronic circuit is like a _______________ to a house?
gate |
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driveway |
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no trespassing sign |
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safe |
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. A transistor acts as a gate or switch for electronic signals.
The rate of flow of electrons per unit time is which of the following?
voltage |
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conductance |
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current |
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resistance |
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 statements about a capacitor is false?
you should always discharge any capacitors before working on an electronic circuit |
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to discharge a capacitor safely, use a high-wattage resistor comparable to the capacitance of the capacitor |
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it is safe to touch a capacitor with your hands as long as it is small |
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a capacitor remains charged even after the input voltage is removed |
The purpose of a capacitor is to retain electric charge and it will do so even after its input voltage is removed. After the input voltage is removed, the capacitor will slowly discharge but, depending on the size and characteristics of the capacitor, discharging could take from a few minutes to a few years. So, it's never safe to touch a capacitor with your hands and you should make sure to discharge any capacitors in a circuit before working on it using an appropriately high-wattage resistor or a capacitor discharge tool.