| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.21 |
| Score | 0% | 64% |
The valence shell of n insulator is how full of electrons?
less than half full |
|
empty |
|
half full |
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more than half full |
Insulators have valence shells that are more than half full of electrons and, as such, are tightly bound to the nucleus and difficult to move from one atom to another.
The voltage output of a transformer primarily depends on which of the following?
the number of turns in the wire of the coils |
|
the diameter of the coils |
|
the diameter of the wire in the coils |
|
the conductor used for the wire in the coils |
A transformer utilizes an inductor to increase or decrease the voltage in a circuit. AC flowing in a coil wrapped around an iron core magnetizes the core causing it to produce a magnetic field. This magnetic field generates a voltage in a nearby coil of wire and, depending on the number of turns in the wire of the primary (source) and secondary coils and their proximity, voltage is induced in the secondary coil.
| 601.5 W | |
| 600 W | |
| 300 W | |
| 540 W |
Which of the following is not a characteristic of a step-up transformer?
has more turns in the secondary winding than in the primary winding |
|
the secondary voltage is higher than the primary voltage |
|
increases voltage |
|
the primary voltage is higher than the secondary 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.
From what energy do photovoltaic cells produce electrical energy?
magnetic |
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sun |
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chemical |
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nuclear |
A photovoltaic cell (also known as a solar cell) converts energy from the sun into electrical energy.