An electric circuit consists of what 3 things?
- power source
- connecting wires or conductors
- a device that uses the electrical energy for some purpose. Also called a load
Basic Electricity Ch2 p.2
What are the three elements needed to have an electrical circuit?
- power source 2. connecting wires 3. a load
Basic Electricity Ch2 p.2
All switches perform the same basic function of…
opening and closing electric circuits
Basic Electricity Ch2 p.3
In a simple electric circuit, the ________ is the device that takes the electrical energy from the power source and uses it to perform some useful function.
Load
Basic Electricity Ch2 p.4
EMF is measured in ______. The amount of voltage supplied by the source determines how much current will flow.
volts
Basic Electricity Ch2 p.5
The factors that determine how much current flows through a dc circuit are the amount of ______ that is supplied by the power source and how well the ___________________.
voltage; load and wires conduct current
Basic Electricity Ch2 p.7
______ is the ease with which a metal allows current to flow.
conductance
Basic Electricity Ch2 p.8
Two factors that determine how much current will flow in a DC circuit are:
Voltage supplied and how well the load/wires conduct current
Basic Electricity Ch2 p.9
What conductor is better than copper?
Silver
Basic Electricity Ch2 p.9
The ______ of any material depends on the number of free electrons the material has.
resistance
Basic Electricity Ch2 p.11
The ______ a wire is, the more resistance it has.
longer
Basic Electricity Ch2 p.12
The _______ of a wire is inversely proportional to its cross section.
resistance
Basic Electricity Ch2 p.13
The materials most often used for resistors are ______.
carbon
Basic Electricity Ch2 p.23
The resistor value may be somewhat higher or lower. To account for these variations, resistors are marked with ______.
tolerance
Basic Electricity Ch2 p.24
The current rating of a resistor is normally given as the ______ of the resistor.
wattage rating
Basic Electricity Ch2 p.25
Advantages of composition resistors are…
small, rugged, and low cost
Basic Electricity Ch2 p.27
The property of maintaining a small tolerance under all operating conditions is called the ______ of a resistor.
stability
Basic Electricity Ch2 p.28
A variable resistor with all 3 terminals connected in a circuit is considered a _________ .
Potentiometer
Basic Electricity Ch2 p.32
When only the center terminal of a variable resistor is used in a circuit it is considered a _________ .
Rheostat
Basic Electricity Ch2 p.32
_________ is the rate at which work is done.
power
Basic Electricity Ch2 p.43
A watt is the power used when ______ flows through a potential difference of ______.
one amp of current, one volt
Basic Electricity Ch2 p.44
Working equipment, such as motors, are based mostly on the power they can use to do ____________ _____________ .
mechanical work
Basic Electricity Ch2 p.50
Electrical work or energy is used by electrical companies to measure and charge for electricity. The basic unit is the ______, but the _______ is more convenient.
watt-hour; kilowatt-hour
Basic Electricity Ch2 p.52
When power sources are connected in series, the total voltage is equal to…
The sum of the individual source voltages
Basic Electricity Ch2 p.58
