| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.83 |
| Score | 0% | 57% |
What is the voltage of most household electrical systems in the United States?
220V |
|
60Hz |
|
60V |
|
110V |
Most households use electricity with a voltage of 110V.
The valence shell of a semiconductor is how full of electrons?
half full |
|
less than half full |
|
more than half full |
|
empty |
Semiconductors have valence shells that are exacly half full and can conduct electricity under some conditions but not others. This property makes them useful for the control of electrical current.
Which of the following allows DC to pass easily but resists the flow of AC?
inductor |
|
capacitor |
|
transformer |
|
semiconductor |
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.
Inductance is a factor in which of the following?
a DC circuit |
|
determining energy stored by a capacitor |
|
an AC circuit |
|
batteries connected in serial |
Inductance is a property of an AC circuit (or a component in an AC circuit) that quantifies resistance to changes in current. The current in an AC circuit is continuously changing and inductive reactance (the opposition to change) depends both on the inductance of the circuit or component and the rate at which the current is changing.
Which of the following is the same for each branch of a parallel circuit?
current |
|
voltage |
|
resistance |
|
power |
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.