| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.57 |
| Score | 0% | 71% |
| 455 V | |
| 227.5 V | |
| 460 V | |
| 457 V |
Ohm's law specifies the relationship between voltage (V), current (I), and resistance (R) in an electrical circuit: V = IR.
V = \( I \times R \) = \( 6.5 \times 70 \) = 455 V
Direct current flows from the __________ terminal of the voltage source to the __________ terminal.
positive, negative |
|
negative, positive |
|
negative, negative |
|
positive, 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.
Which of the following allows encapsulating complex circuit designs for easier integration into electronic devices and machines?
parallel circuits |
|
integrated circuits |
|
series circuits |
|
series-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 |
|
a capacitor remains charged even after the input voltage is removed |
|
to discharge a capacitor safely, use a high-wattage resistor comparable to the capacitance of the capacitor |
|
you should always discharge any capacitors before working on an electronic circuit |
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.
This circuit component symbol represents a(n):
capacitor |
|
diode |
|
fuse |
|
potentiometer |
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.