| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.73 |
| Score | 0% | 75% |
Why does current in an electric circuit create heat?
the wire in the circuit burns when current passes through |
|
heat is created when the current overcomes resistance in the wire |
|
voltage is naturally hot |
|
current is naturally hot |
Current in an electric circuit creates heat when the current overcomes resistance in the wire.
Resistance is measured in:
ohms |
|
coulombs |
|
amperes |
|
volts |
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.
Longer the electrical wires mean _______________ voltage drop.
complete |
|
greater |
|
lesser |
|
diminishing |
Electrical wires have a certain amount of resistance per foot. A longer wire means more resistance and a greater voltage drop.
Using a fuse with a current rating higher than that required by a circuit:
makes the circuit less safe |
|
is required |
|
makes no difference |
|
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.
The valence shell of a semiconductor is how full of electrons?
empty |
|
less than half full |
|
half full |
|
more than half full |
Semiconductors have valence shells that are exacly half full and can conduct electricity under some conditions but not others. This property makes them useful for the control of electrical current.