| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.24 |
| Score | 0% | 65% |
| 39 Ω | |
| 30 Ω | |
| 60 Ω | |
| 45 Ω |
Ohm's law specifies the relationship between voltage (V), current (I), and resistance (R) in an electrical circuit: V = IR.
Solved for resistance, R = \( \frac{V}{I} \) = \( \frac{180}{6} \) = 30 Ω
What is the frequency of most household electrical systems?
60Hz |
|
110Hz |
|
60MHz |
|
110V |
Electricity is delivered from power stations to customers as AC because it provides a more efficient way to transport electricity over long distances. Most households use electricity with a frequency of 60Hz.
Which of the following allows DC to pass easily but resists the flow of AC?
capacitor |
|
inductor |
|
semiconductor |
|
transformer |
An inductor is coiled wire that stores electric energy in the form of magnetic energy and resists changes in the electric current flowing through it. If current is increasing, the inductor produces a voltage that slows the increase and, if current is decreasing, the magnetic energy in the coil opposes the decrease to keep the current flowing longer. In contrast to capacitors, inductors allow DC to pass easily but resist the flow of AC.
This circuit component symbol represents a(n):
fuse |
|
diode |
|
capacitor |
|
resistor |
Fuses are thin wires that melt when the current in a circuit exceeds a preset amount. They help prevent short circuits from damaging circuit components when an unusually large current is applied to the circuit, either through component failure or spikes in applied voltage.
Which of the following is not a terminal on a transistor?
base |
|
collector |
|
input |
|
emitter |
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.