| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.50 |
| Score | 0% | 70% |
Which of the following is not a terminal on a transistor?
input |
|
base |
|
emitter |
|
collector |
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.
From what energy do photovoltaic cells produce electrical energy?
nuclear |
|
magnetic |
|
chemical |
|
sun |
A photovoltaic cell (also known as a solar cell) converts energy from the sun into electrical energy.
Resistance and current are __________ proportional.
directly |
|
exponentially |
|
not |
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inversely |
Resistance is opposition to the flow of current and is measured in ohms (Ω). One ohm is defined as the amount of resistance that will allow one ampere of current to flow if one volt of voltage is applied. As resistance increases, current decreases as resistance and current are inversely proportional.
Silver and gold are among the most highly conductive elements. Why is copper used much more often as a conductor in electrical circuits?
silver and gold are costly |
|
all of these |
|
copper is durable and relatively cheap |
|
silver and gold are brittle |
All conductors have resistance and the amount of resistance varies with the element. But, resistance isn't the only consideration when choosing a conductor as the most highly conductive elements like silver and gold are also more expensive and more brittle than slightly less conductive elements like copper. A balance needs to be struck between the electrical qualities of a material and its cost and durability.
Longer the electrical wires mean _______________ voltage drop.
lesser |
|
diminishing |
|
greater |
|
complete |
Electrical wires have a certain amount of resistance per foot. A longer wire means more resistance and a greater voltage drop.