| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.23 |
| Score | 0% | 65% |
In an electrical circuit, resistors have fixed or __________ resistance.
series |
|
dynamic |
|
parallel |
|
variable |
Resistors are used to limit voltage and/or current in a circuit and can have a fixed or variable resistance. Variable resistors (often called potentiometers or rheostats) are used when dynamic control over the voltage/current in a circuit is needed, for example, in a light dimmer or volume control.
This circuit component symbol represents a(n):
transformer |
|
inductor |
|
fuse |
|
potentiometer |
Resistors are used to limit voltage and/or current in a circuit and can have a fixed or variable resistance. Variable resistors (often called potentiometers or rheostats) are used when dynamic control over the voltage/current in a circuit is needed, for example, in a light dimmer or volume control.
Which of the following is not a characteristic of a step-up transformer?
the secondary voltage is higher than the primary voltage |
|
increases voltage |
|
has more turns in the secondary winding than in the primary winding |
|
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.
Which of the following allows encapsulating complex circuit designs for easier integration into electronic devices and machines?
series-parallel circuits |
|
integrated circuits |
|
series circuits |
|
parallel circuits |
Circuits containing transistors are packaged into integrated circuit chips that allow encapsulating complex circuit designs (CPU, memory, I/O) for easier integration into electronic devices and machines.
Which of the following statements about a capacitor is false?
it is safe to touch a capacitor with your hands as long as it is small |
|
you should always discharge any capacitors before working on an electronic circuit |
|
to discharge a capacitor safely, use a high-wattage resistor comparable to the capacitance of the capacitor |
|
a capacitor remains charged even after the input voltage is removed |
The purpose of a capacitor is to retain electric charge and it will do so even after its input voltage is removed. After the input voltage is removed, the capacitor will slowly discharge but, depending on the size and characteristics of the capacitor, discharging could take from a few minutes to a few years. So, it's never safe to touch a capacitor with your hands and you should make sure to discharge any capacitors in a circuit before working on it using an appropriately high-wattage resistor or a capacitor discharge tool.