ELECTRONICS Flashcards
Electronics
What do volts measure?
The difference of potential between two points.
What do amperes (amps) measure?
The number of electrons that move past a specific point in one second.
What do ohms measure?
Resistance, including anything that could limit the flow of electrons.
What is a current?
Something that occurs when electrons move from one place to another.
What is the purpose of a conductor?
It allows electrons to move freely.
What does an insulator do?
Discourage electric currents.
What does a watt measure?
Power, the rate at which electrical energy is consumed or formed into another type of energy.
What is a watt-hour?
The amount of energy used in one hour at a rate of one watt.
What is a kilowatt-hour?
Most electricity is measured in this. It’s how much energy you would use of you ran a 1000 watt (1kilowatt) device for an hour
How do you find watt-hours?
Multiply wattage by time (hours)
What is a circuit?
The path of an electrical current
What supplies the voltage in a circuit?
The battery
What is a current?
Something that occurs when electrons move from one place to another.
What is the purpose of a conductor?
It allows electrons to move freely.
What does an insulator do?
Discourage electric currents.
What does a watt measure?
Power, the rate at which electrical energy is consumed or formed into another type of energy.
What is a watt-hour?
The amount of energy used in one hour at a rate of one watt.
What is a kilowatt-hour?
Most electricity is measured in this. It’s how much energy you would use of you ran a 1000 watt (1kilowatt) device for an hour
What do volts measure?
The difference of potential between two points.
What do amperes (amps) measure?
The number of electrons that move past a specific point in one second.
What do ohms measure?
Resistance, including anything that could limit the flow of electrons.
What is a current?
Something that occurs when electrons move from one place to another.
What is the purpose of a conductor?
It allows electrons to move freely.
What does an inulator do?
Discourage electric currents.
What does a watt measure?
Power, the rate at which electrical energy is consumed or formed into another type of energy.
What is a watt-hour?
The amount of energy used in one hour at a rate of one watt.
What is a kilowatt-hour?
Most electricity is measured in this. It’s how much energy you would use of you ran a 1000 watt (1kilowatt) device for an hour
How do you find watt-hours?
Multiply wattage by time (hours)
What is a circuit?
The path of an electrical current
What supplies the voltage in a circuit?
The battery
What is ground?
Any part of a circuit that measures 0 volts.
How do you measure volts in a circuit?
A voltmeter or multimeter.
What is a cell?
A storage compartment for electricity in a battery.
What is an electrical current?
The rate of flow of electrons in a conductor.
What do coulombs measure?
Charge. It is the amount of electricity provided by a current of one amp flowing for one second.
What does an amp represent?
The strength of a current.
What is an ammeter?
Measures the flow of current through a circuit.
What determines the number of amps along a wire?
The amount of voltage and the resistance in a circuit.
What is a circuit breaker?
a device thy automatically interrupts the electrical current
What is a rheostat?
It varies the resistance without opening the circuit. It absorbs all the electricity an application doesn’t use. ( dimmer switch)
What does an ohm represent?
The amount of resistance that interferes with the flow.
How is resistance measured?
By dividing the voltage measured at any given point (voltmeter) by the amount of current at the same point in a circuit (ammeter)
What three influences are present in a current flowing through a wire?
- ) amount of voltage (volts)
- ) resistance to the current (ohms)
- ) amount of current (amps)
What is ohms law?
The current in a circuit is directly proportional to the applied voltage an inversely proportional to the circuit resistance.
What is the formula for currents (amps)?
Current=voltage/resistance or I=E/R
What is the formula for voltage (volts)?
Voltage=current X resistance or E=IR
What is the formula for resistance (ohms)?
Resistance= voltage/current or R=E/I
In a circuit, electricity follows the path of…
least resistance
What is a conventional current?
The flow of electricity from the negative terminal to the positive terminal.
What is a short circuit?
When any wire accidentally crosses over another wire, causing the electricity to bypass the rest of the circuit and not follow the intended path.
How is a chemical effect produced?
A current passes through a chemical compound and breaks that compound up.
What is an electrolytic decomposition?
A chemical effect
What is electroplating?
A process used to cover objects with a very thin, coating of metal.
How is a heat effect produced?
Conducting electricity causes wires to become heated. Heat develops because the current must overcome the resistance of the wire.
How is a magnetic effect produced?
When a wire is introduced to a magnetic field, electricity flows though the wire and creates a magnetic field that repels a magnet.
What is an electromagnetic induction?
A magnetic effect
How is a physiological effect produced?
Current passes through your muscles and causes the muscle to contract.
what is a direct current?
A current that only flows in one direction.
What is an alternating current?
A current that constantly changes dierention in a regular pattern.
What is the frequency of an ac?
The number of times an ac changes direction per second.
What is a hertz?
Unit of measurement for frequency.
What is the Capacitance property?
The storage of energy that occurs in a nonconductor. This property resists any change in voltage in a circuit.
What is the Inductance property?
It causes an electromotive force to be induced in a circuit.
How is impedance expressed?
Electromotive force/current
What is electromotive force?
Voltage
What is a transistor?
A semiconductor that controls the flow of electricity in a circuit that can amplify a signal. Usually made of germanium or silicone.
What is rectification?
The process of changing alternating currents to direct currents.
What is a rectifier?
A circuit that performs rectification.
What are semiconductor diodes?
Components made of a material with conductivity somewhere between that of a conductor and an insulator.
What are diodes?
Conduct electricity in only one dicrection.
What are three terminals in a transistor?
- ) Base
- ) Collector
- ) Emitter
What is an emittor?
A voltage output
What is base?
Controls the flow of current through a transmittor.
What is a collector?
A voltage input.
What is a complex system?
Two circuits combined.
What is a block diagram?
Shows the various combined circuits that form a complex system.
What is an inductor?
A coil of wire that creates a magnetic field when current passes through it.
What is push switch?
Allows current to pass flow only when the button is pushed. (doorbell)
What is a push-to-break switch?
The circuit is normally closed (device is on), and the circuit is open (device is off) only when the button is pressed.
What is a on/off switch?
Allows current to flow only when it’s in the closed (on) position.
What is a two-way switch?
Directs the flow of current to one of two routes, according to it’s position.
What is a dual on/off switch?
Often used to switch main electricity because it can isolate both the live and neutral connections.
What is a relay switch?
An electrically operated switch that may operate multiple switches at one time. Current flowing through a coil sets up a magnetic field, which causes the lever(s) to move, effectively changing the (relay) switch’s position(s).
What is the value of a black band?
0
What is the value of a brown band?
1
What is the value of a red band?
2
What is the value of an orange band?
3
What is the vallue of a yellow band?
4
What is the value of a green band?
5
What is the value of a blue band?
6
What is the value of a violet band?
7
What is the value of a gray band?
8
What is the value of a white band?
9
What do the bands on a resistor represent?
The first and second bands are the first two digits in the resistor’s value. The next band is the multiplier (number of zeros after the first two numbers). (OHMS)
What does a gold or silver band after the first two bands indicate?
Tolerance.
What are three variable resistors?
- ) Rheostat
- ) Potentiometer
- ) Preset Variable Resistor
What are nonvariable resistors?
Color bands.
What is a rheostat?
A variable resistor with two contacts usually used to control current. (LAMP BRIGHTNESS)
What is a potentiometer?
A variable resistor with three contacts used to control voltage.
What is a preset variable resistor?
A device that operates with a small screwdriver or similar tool; designed to be set when the circuit is made and then left without further adjustment.
What is a capacitor?
Stores electric charge. Used with resistors in timing circuits because it takes time for a capaacitor to fill with charge. Also used to filter circuits because they easily pass AC signals but they block DC signals.
What is a polarized capacitor?
Must be connected the correct way in a circuit.
What is a variable capacitor?
Used in radio tuning circuits.
What is a diode?
Allows electricity to only flow in one direction. The electrical version of a valve.
What is a light-emmitting diode(LED)?
Emmits a light when an electrical current passes through it.
What is a zener diode?
Allows current to flow in the opposite direction after a threshold is met.
What is a transistor?
Amplifies currents.
What is an amplifier?
A complex circuit used to maginify power, current, or voltage.
What is an antenna?
A device designed to recieve and/or transmit radio signals.
