| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.27 |
| Score | 0% | 65% |
Direct current flows from the __________ terminal of the voltage source to the __________ terminal.
negative, negative |
|
positive, negative |
|
positive, positive |
|
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.
The rate of flow of electrons per unit time is which of the following?
conductance |
|
resistance |
|
current |
|
voltage |
Current is the rate of flow of electrons per unit time and is measured in amperes (A). A coulomb (C) is the quantity of electricity conveyed in one second by a current of one ampere.
Inductance is a factor in which of the following?
determining energy stored by a capacitor |
|
an AC circuit |
|
a DC 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 will increase the magnetic field produced by the electric current in a wire?
wind the wire into a coil |
|
wrap the wire around a ceramic core |
|
construct the wire from insulative material |
|
construct the wire from conductive material |
A moving electric current produces a magnetic field proportional to the amount of current flow. This magnetic field can be made stronger by winding the wire into a coil and further enhanced if done around an iron containing (ferrous) core.
The conductivity of an element depends on how many electrons occupy which electron shell?
first |
|
outer |
|
inner |
|
middle |
All electricity is the movement of electrons which are subatomic particles that orbit the nucleus of an atom. Electrons occupy various energy levels called shells and how well an element enables the flow of electrons depends on how many electrons occupy its outer (valence) electron shell.