N-type material has a surplus of____
electrons
P-type material has positively charged spaces called____
holes
substances that can be made to conduct electricity under certain conditions are called
semiconductors
semiconductor devices used in electronic circuits can be called ___ devices
solid-state
the positively charged side of a diode is called the___
anode
the negatively charged side of a diode is called the
cathode
a diode setup is ____ based if the positive terminal or a bettery is connected to the cathode and the negative terminal is connected to the anode
reverse
a diode setup is ____ biased if the positive terminal of a battery is connected to the anode and the negative terminal is connected to the cathode
forward
a semiconductor or solid-state device used to control the flow of current is an ____ device
electronic
electrons will only flow through a diode from the ____
cathode to the anode
A ____ is a device that converts an input signal from one form of energy to an output signal of another form of energy
transducer
in HVACR, .any sensors are also ____ because they produce an electrical output signal while monitoring a different input signal
transducers
an ____ is a solid-state device that allows current to flow in both directions
diac
A diac stays in conduction mode as long as the ____ stays above the threshold value
Holding Current
Silicon-controlled rectifiers are often used to convert dc voltage to ac voltage in a device called an
inverter
A ____ installed in a gas furnace stops producing a voltage when the pilot light flame goes out
thermocouple
negative temperature coefficient (NTC) thermistors decrease their resistance as their temperature
increases
positive temperature coefficient (PTC) thermistors increase their resistance as their temperature
increases
A ___ is a layered, three-terminal semiconductor device that is used to either switch or amplify an electrical signal
transistor
an ___ is an electronic circuit that converts ac to dc
rectifer
A ____ is a connected series of thermocouple leads used to produce a higher voltage signal
thermopile
as the tempture of a motor increases, the ___ of a PTC thermistor also increases to stop the motor
resistance
____ turn electrical energy into mechanical motion
solenoids
diffrent pairs of metals are joined in ___ to produce different voltages
thermocouples
the enclosed contacts of a relay are operated by
electromagnet
the contacts in a normally closed (NC) switch are open when the switch is actuated. True or False
true
Semiconductors are substances that can be made to conduct electricity under certain conditions true or false
True
impurities are added to a pure semiconductor to alter its conductivity. True or False
true
there are no moving parts in a semiconductor
true
a diode is a solid-state device composed of onlu p-type material True or False
false
The negatively charged side of a diode is called the anode
true or false
false
the negatively charged side of a diode is called the anode
true or false
false
Current will flow through a diode when the positive terminal of a battery is connected to the cathode and the negative terminal is connected to the anode
true or false
false
sensors are devices that detect and respond to some kind of stimulus
true or false
true
in order for current to flow through a diac, the applied voltage must reach or exceed the diacs breakover voltage
true or false
true
applied voltage below the breakover voltage will not be able to force current through a diac
true or false
true
a silicon-controlled rectifier (SCR) conducts current from anode to cathode
true or false
false
a triac can conduct current in both directions for alternating current
true
a triac will continue to conduct current even if the gate circuit is open
true or false
true
in HVACR, thermistors may be used to stop electrical power from going to an overheating motor
true or false
true
an inverter converts alternating current to direct current
false
adding impurities to a pure semiconductor is called doping
true or false
true
a microprocessor functions as the contorl center of a system and can accept information, store it, and react in some preset way.
true or false
true
a bridge rectifier produces a direct current output for only one-half of the ac sine wave
false
a half-wave rectifer produces a direct current output with no gaps between the waves
true or fasle
false