| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.00 |
| Score | 0% | 60% |
What kind of diode allows current to flow in the opposite direction once a certain voltage threshold is reached?
light emitting diode |
|
standard diode |
|
v-type diode |
|
zener diode |
A diode allows current to pass easily in one direction and blocks current in the other direction. A zener diode is a diode which allows current to flow in one direction as normal and will also allow current flow in the reverse direction when the voltage is above a certain value. This value is called the breakdown voltage.
What is the frequency of most household electrical systems?
110Hz |
|
110V |
|
60Hz |
|
60MHz |
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 is not a terminal on a transistor?
input |
|
collector |
|
emitter |
|
base |
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.
Direct current flows from the __________ terminal of the voltage source to the __________ terminal.
negative, negative |
|
positive, positive |
|
positive, negative |
|
negative, positive |
Direct current flows in only one direction in a circuit, from the negative terminal of the voltage source to the positive. A common source of direct current (DC) is a battery.
A capacitor is often used for which of the following purposes?
as a primary power source |
|
to maintain power in a circuit when the primary power source is disconnected |
|
to allow a small amount of current to control a large amount of current |
|
to convert alternating current into direct current |
Capacitors store electricity and are used in circuits as temporary batteries. Capacitors are charged by DC current (AC current passes through a capacitor) and that stored charge can later be dissipated into the circuit as needed. Capacitors are often used to maintain power within a system when it is disconnected from its primary power source or to smooth out or filter voltage within a circuit.