| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.41 |
| Score | 0% | 68% |
Which of the following is not a characteristic of a step-up transformer?
the secondary voltage is higher than the primary voltage |
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has more turns in the secondary winding than in the primary winding |
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the primary voltage is higher than the secondary voltage |
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increases 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.
Using a fuse with a current rating higher than that required by a circuit:
is required |
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makes the circuit less safe |
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makes no difference |
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is recommended |
A fuse is a type of low resistance resistor that stops current flow in a circuit in response to a larger than intended electric current flow. Using a fuse with a higher current rating than required by a circuit is less safe as it could potentially allow overcurrent and risk a fire or heat-related equipment damage.
Which of the following is not a terminal on a transistor?
emitter |
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base |
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collector |
|
input |
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.
| 2.5 A | |
| 2.75 A | |
| 4.5 A | |
| 0.83 A |
Ohm's law specifies the relationship between voltage (V), current (I), and resistance (R) in an electrical circuit: V = IR.
Solved for current, I = \( \frac{V}{R} \) = \( \frac{225}{90} \) = 2.5 A
Which of the following statements about a capacitor is false?
it is safe to touch a capacitor with your hands as long as it is small |
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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 |
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.