| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.34 |
| Score | 0% | 67% |
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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a capacitor remains charged even after the input voltage is removed |
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it is safe to touch a capacitor with your hands as long as it is small |
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.
This circuit diagram represents a(n):
open circuit |
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series-parallel circuit |
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parallel circuit |
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series circuit |
A series circuit has only one path for current to flow. In a series circuit, current (I) is the same throughout the circuit and is equal to the total voltage (V) applied to the circuit divided by the total resistance (R) of the loads in the circuit. The sum of the voltage drops across each resistor in the circuit will equal the total voltage applied to the circuit.
The formula specifying Ohm's law is which of the following?
\(V = {I \over R}\) |
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V = I2R |
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V = IR |
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\(V = {R \over I}\) |
Ohm's law specifies the relationship between voltage (V), current (I), and resistance (R) in an electrical circuit: V = IR.
The diameter of a number 12 wire is __________ the diameter of a number 6 wire?
less than |
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triple |
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double |
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more than |
The larger the number the smaller the diameter of the wire. So, the diameter of a number 12 wire is less than the diameter of a number 6 wire.
An inductor __________ changes in the electric current flowing through it.
doubles |
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resists |
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enhances |
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eliminates |
An inductor is coiled wire that stores electric energy in the form of magnetic energy and resists changes in the electric current flowing through it. If current is increasing, the inductor produces a voltage that slows the increase and, if current is decreasing, the magnetic energy in the coil opposes the decrease to keep the current flowing longer. In contrast to capacitors, inductors allow DC to pass easily but resist the flow of AC.