| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.30 |
| Score | 0% | 66% |
Voltage and current are __________ proportional.
not |
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directly |
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inversely |
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indirectly |
Voltage (V) is the electrical potential difference between two points. Electrons will flow as current from areas of high potential (concentration of electrons) to areas of low potential. Voltage and current are directly proportional in that the higher the voltage applied to a conductor the higher the current that will result.
| 54V 10A | |
| 27V 30A | |
| 9V 60A | |
| 54V 60A |
Connecting the 6 batteries in series multiplies their voltage while keeping their current the same yielding a 54V 10A configuration. Connecting the 6 batteries in parallel multiplies their current while keeping their voltage the same yielding a 9V 60A configuration. Using a series-parallel connection, 3 batteries can be connected in series and 3 can be connected in parallel resulting in a 27V 30A configuration.
Electrical power is measured in:
watts |
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coulombs |
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amperes |
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volts |
Electrical power is measured in watts (W) and is calculated by multiplying the voltage (V) applied to a circuit by the resulting current (I) that flows in the circuit: P = IV. In addition to measuring production capacity, power also measures the rate of energy consumption and many loads are rated for their consumption capacity. For example, a 60W lightbulb utilizes 60W of energy to produce the equivalent of 60W of heat and light energy.
This circuit component symbol represents a(n):
fuse |
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potentiometer |
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diode |
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capacitor |
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.
Which of the following statements about a capacitor is false?
to discharge a capacitor safely, use a high-wattage resistor comparable to the capacitance of the capacitor |
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you should always discharge any capacitors before working on an electronic circuit |
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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.