| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.26 |
| Score | 0% | 65% |
What is the primary difference between a rectifier and an inverter?
a rectifier strips out the AC portion of electricity while an inverter strips out the DC portion |
|
a rectifier strips out the DC portion of electricity while an inverter strips out the AC portion |
|
a rectifier converts a DC input to AC while an inverter converts an AC input to DC |
|
a rectifier converts an AC input to DC while an inverter converts a DC input to AC |
A diode allows current to pass easily in one direction and blocks current in the other direction. Diodes are commonly used for rectification which is the conversion of alternating current (AC) into direct current (DC). Because a diode only allows current flow in one direction, it will pass either the upper or lower half of AC waves (half-wave rectification) creating pulsating DC. Multiple diodes can be connected together to utilize both halves of the AC signal in full-wave rectification.
A capacitor is often used for which of the following purposes?
to allow a small amount of current to control a large amount of current |
|
to convert alternating current into direct current |
|
to maintain power in a circuit when the primary power source is disconnected |
|
as a primary power source |
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.
Which of the following allows DC to pass easily but resists the flow of AC?
transformer |
|
inductor |
|
semiconductor |
|
capacitor |
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 diagram represents a(n):
parallel circuit |
|
series-parallel circuit |
|
rectifier |
|
series circuit |
In a parallel circuit, each load occupies a separate parallel path in the circuit and the input voltage is fully applied to each path. Unlike a series circuit where current (I) is the same at all points in the circuit, in a parallel circuit, voltage (V) is the same across each parallel branch of the circuit but current differs in each branch depending on the load (resistance) present.
Which of the following statements about a capacitor is false?
a capacitor remains charged even after the input voltage is removed |
|
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 |
|
it is safe to touch a capacitor with your hands as long as it is small |
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.