Asvab Electronics Information
10. Components designed to store electrical charge are called (A) capacitors. (B) transformers. (C) resistors. (D) transistors.
A. Capacitors store electric charge. They're used with resistors in timing circuits because it takes time for a capacitor to store voltage (to become charged). The correct answer is Choice (A).
11. In what direction does current go in electron flow notation? (A) from negative to positive (B) from positive to negative (C) any direction (D) horizontally
A. In conventional flow notation, the motion of charge is shown according to the (technically incorrect) labels of + and -, with the electric charge moving from positive to negative. But in electron flow notation, the actual motion of electrons in the circuit is followed. Negative electrons are always searching for positive charges, so current flows from a negative pole to a positive pole.
How does a rheostat lower the resistance in an electrical circuit? (A) It absorbs the electrical current. (B) It turns off the circuit. (C) It trips the breaker. (D) It burns the fuse.
A. It absorbs the electrical current. A rheostat can vary the resistance without opening the circuit by absorbing some of the electrical current flowing through it. (Think of a dimming light switch.)
What is the difference between capacitive reactance and inductive reactance? (A) One opposes changes in voltage, and the other opposes changes in current. (B) One can only be used with a battery. (C) One is alternating current, and the other is direct current. (D) One is only used with magnets.
A. One opposes changes in voltage, and the other opposes changes in current. Capacitive reactance is an opposition to the change in voltage across an element. Inductive reactance is an opposition to the change in current on an inductive element.
16. What is commonly used in a circuit in which the flow of electricity needs to be regulated for the device to run properly? (A) resistance (B) transformer (C) diodes (D) batteries
A. Resistance is set up in a circuit to regulate the electricity so the device isn't destroyed by electrical heat.
What occurs when a light blows out in a series circuit? (A) The series completely breaks. (B) The remaining components still work. (C) The power to the blown light is lost. (D) The battery stores the lost energy from the blown light.
A. The series completely breaks. In a series, all the components must function in order for the circuit to work. A good way to remember a series circuit is to think of Christmas lights. When one bulb comes out, the circuit becomes open and can't provide current to the other lights.
What does the acronym VAC stand for in electronics? (A) Voltage Alternating Current (B) Voltage And Current (C) Variable Aided Current (D) Voltage Amplified Capacitor
A. Voltage Alternating Current VAC is an acronym for Voltage Alternating Current and is usually abbreviated next to a measurement of volts, indicating the power of battery in a household product.
What is a flex sensor? (A) a resistor (B) a transistor (C) a diode (D) a switch
A. a resistor A flex sensor is a resistor that changes its resistance based on being bent or flexed.
Magnetic cores usually consist of what substances? (A) air or iron (B) copper or iron (C) air or copper (D) air or wood
A. air or iron Most coils are either classified as air or soft iron, based on their cores.
What is another name for electrolytic decomposition? (A) chemical effect (B) heat effect (C) magnetic effect (D) physiological effect
A. chemical effect Current produces this effect when it passes through a chemical compound and breaks it down.
What is another word for a wire? (A) conductor (B) transformer (C) diode (D) resistor
A. conductor A conductor is a substance that conducts an electrical charge; a wire is just one example.
What is the electrical version of a valve called? (A) diode (B) transformer (C) capacitor (D) switch
A. diode A diode was once called a valve, and it allows electricity to flow in one direction.
Which of the following is an example of a transducer turning electrical energy to sound? (A) doorbell (B) tuner (C) clock (D) light bulb
A. doorbell A doorbell is a transducer that converts electrical energy to sound.
In what direction does current go in electron flow notation? (A) from negative to positive (B) from positive to negative (C) any direction (D) horizontally
A. from negative to positive In conventional flow notation, the motion of charge is shown according to the (technically incorrect) labels of + and -, with the electric charge moving from positive to negative. But in electron flow notation, the actual motion of electrons in the circuit is followed. Negative electrons are always searching for positive charges, so current flows from a negative pole to a positive pole.
What is the unit of measurement for frequency? (A) hertz (B) ohms (C) amperes (D) watts
A. hertz The number of hertz equals the number of cycles per second of frequency.
What is the ratio of electromotive force to current? (A) impedance (B) power (C) magnetism (D) voltage
A. impedance Impedance is an opposition to the flow of electrons in an AC circuit. It's a combination of resistance, capacitive reactance, and inductive reactance. You can express impedance as the ratio of electromotive force (voltage) to current.
The following circuit diagram represents what common household device? (A) lamp (B) doorbell (C) ceiling fan (D) microwave
A. lamp The circuit diagram shows symbols for a battery, a switch, and a light source, consistent with a lamp circuit.
What is commonly used in a circuit in which the flow of electricity needs to be regulated for the device to run properly? (A) resistance (B) transformer (C) diodes (D) batteries
A. resistance Resistance is set up in a circuit to regulate the electricity so the device isn't destroyed by electrical heat.
What does the following symbol represent? (A) resistor (B) inductor (C) current source (D) electricity
A. resistor The symbol represents a resistor. This device provides resistance, which opposes electrical current.
What is the term for excess electricity that is trapped on the surface of an object? (A) static (B) magnetic (C) positive (D) negative
A. static A static electrical charge is created whenever two surfaces come together and then separate, trapping electrical charges on the surface of the object.
What does the following symbol represent? (A) transistor (B) amplifier (C) potentiometer (D) heater
A. transistor The symbol represents a transistor, which controls the flow of electricity in a circuit.
What color wire is not commonly used as a switch leg wire? (A) white (B) blue (C) yellow (D) orange
A. white Blue, yellow, and orange wires are used as three- and four-way switch applications; they become hot when turned on.
5. What is the point at which electrical connections (such as two wires) are made? (A) terminal (B) trigger (C) transmitter (D) transformer
B. A terminal is a device that connects electrical circuits together, a trigger initiates a circuit action, a transmitter is a device used to achieve transmission, and a transformer is an inductor with two or more windings. Windings are magnetic wires that are coated with enamel and wrapped around the core of a transformer. The primary winding is driven by transistors, and the secondary winding is driven by the core's magnetic field, produced by the primary winding. Choice (B) is the correct answer.
What can be concluded from the following diagram? (A) It produces heat. (B) It produces sound. (C) It produces light. (D) None of the above.
B. It produces sound. You can conclude that the device produces sound because there's a speaker on the circuit:
7. What process changes incoming alternating current (AC) to direct current (DC)? (A) magnetic effect (B) rectification (C) transformation (D) impedance
B. Rectification occurs in certain electronic circuits that need to change incoming AC to DC in order to run properly.
What does the following symbol represent? (A) bell (B) relay (C) heater (D) fuse
B. Relay The symbol represents a relay switch, which is an electrically operated switch that can operate multiple switches at one time.
What conclusion can you draw based on the following diagram of a flashbulb circuit? (A) There is no power to the circuit. (B) The flashbulb is turned off. (C) Only one battery is working. (D) The flashbulb is in parallel.
B. The flashbulb is turned off. When the switch is in contact with point A (as shown), the charges are being stored. When the switch moves to point B, the flashbulb turns on.
What occurs when a light blows out in a parallel circuit? (A) The series completely breaks. (B) The remaining components still work. (C) The power to the blown light is lost. (D) The battery stores the lost energy from the blown light.
B. The remaining components still work. In a parallel circuit, each light has its own circuit, so if a bulb blows, the remaining components are still able to function. A good way to remember a parallel circuit is to think of a light switch in your home that turns on multiple lights. If one bulb goes out, the other lights will still function.
What is true about parallel circuits? (A) The voltage decreases along the circuit. (B) The voltage is applied evenly to each branch. (C) The voltage increases along the circuit. (D) The voltage is divided unevenly across the circuit.
B. The voltage is applied evenly to each branch. In a parallel circuit, the current is divided unevenly to each branch, and the voltage is applied evenly.
4. What conclusion can you draw based on the following diagram of a flashbulb circuit? (A) There is no power to the circuit. (B) The flashbulb is turned off. (C) Only one battery is working. (D) The flashbulb is in parallel.
B. When the switch is in contact with point A (as shown), the charges are being stored. When the switch moves to point B, the flashbulb turns on.
12. In an electronic circuit diagram, the symbol used to show wires connecting is a/an (A) X symbol. (B) dot. (C) dark square. (D) T symbol.
B. Wires connected to each other are indicated by a darkened circle. The correct answer is Choice (B).
What is an electric cell? (A) battery power (B) a storage compartment for electricity in a battery (C) the voltage a battery creates (D) a measurement of battery power
B. a storage compartment for electricity in a battery The cells in a battery hold equal amounts of voltage; just how much depends on their size and construction.
What semiconductor contains at least three terminals called an emitter, a base, and a collector? (A) a parallel circuit (B) a transistor (C) a transducer (D) a transformer
B. a transistor A transistor controls the flow of electricity in a circuit by using an emitter (voltage output), a base (the control), and the collector (voltage input).
What is the main function of a diode? (A) makes alternating current (B) allows the current to flow in one direction (C) emits light (D) provides a power source
B. allows the current to flow in one direction A diode is a two-terminal electric component that allows electricity to flow in one direction or changes alternating current to direct current.
Most electricity comes in the form of what? (A) direct current (B) alternating current (C) wires (D) batteries
B. alternating current Higher voltages are easier to transport and create using alternating current, so most electricity is created using this method.
What represents the strength of a current? (A) coulomb (B) ampere (C) voltage (D) wires
B. ampere Amperes (amps) measure the number of electrons that move past a specific point in one second.
What device is the following schematic most likely showing? (A) an engine (B) an intercom (C) a microwave (D) an oven
B. an intercom The schematic shown is for a two-way intercom. A close look reveals two speakers, one at the beginning and one at the end of the circuit.
What draws current as it absorbs energy? (A) inductor (B) capacitor (C) transformer (D) transistor
B. capacitor A capacitor is a passive two-terminal electrical component used to store energy in an electric field. When a capacitor is faced with an increasing voltage, it acts as a load by drawing current as it absorbs energy.
What do the following symbols represent? (A) transformers (B) capacitors (C) transistors (D) lamps
B. capacitors A capacitor is a passive two-terminal electrical component used to store energy in an electric field.
What do the following symbols represent? (A) resistors (B) capacitors (C) voltage (D) batteries
B. capacitors Capacitors store electrical charge. A capacitor is polarized when charge can flow through the capacitor in only one direction.
What does the following symbol represent? (A) rheostat (B) cathode (C) diode (D) capacitor
B. cathode The symbol represents a cathode — an electrode through which electrical current exits a polarized electrical device.
What does the following symbol represent? (A) battery (B) cell (C) buzzer (D) heater
B. cell The symbol represents a cell, which supplies voltage.
Amperes is a unit of measurement for what? (A) power (B) current (C) resistance (D) music
B. current The ampere, or amp, is a unit of electric current.
What does the following symbol represent? (A) alternating current (B) direct current (C) diode (D) resistance
B. direct current The symbol represents direct current (DC), which is the unidirectional flow of electrical charge.
What is the term for the number of times a current completes two alternations of direction per second? (A) capacitance (B) frequency (C) power (D) lap
B. frequency Frequency, measured in hertz (Hz), is the number of times an alternating current changes direction per second.
What symbol is not shown in the following circuit diagram? (A) transformer (B) fuse (C) resistor (D) transistor
B. fuse This symbol represents a fuse; the circuit doesn't contain a fuse.
What causes wires to become heated when conducting electricity? (A) chemical effect (B) heat effect (C) magnetic effect (D) physiological effect
B. heat effect Heat develops when conducting electricity because the current must overcome the resistance of the wire.
What is the term for a material whose internal electric charges do not flow freely and which, therefore, does not conduct an electric current? (A) semiconductor (B) insulator (C) conventional current (D) short circuit
B. insulator An insulator (like wood, rubber, or air) doesn't conduct electric current and, in many cases, prevents the flow of electrons.
How is electrical energy usually measured? (A) watt-hours (B) kilowatt-hours (C) volt-hours (D) current-watts
B. kilowatt-hours Electrical energy is usually measured in kilowatt-hours.
What do the following symbols represent? (A) batteries (B) lamps (C) wires (D) speakers
B. lamps The symbol with the X represents an indicator lamp, while the symbol with a half-circle represents a lighting lamp.
What term describes any device that consumes the energy flowing through a circuit and converts that energy into work? (A) meter (B) load (C) power (D) frequency
B. load A load consumes the electricity from a circuit and converts it into work.
What causes electrons in a direct current to flow in a single direction on a wire? (A) electrical energy (B) magnetic field (C) parallel circuit (D) radiation
B. magnetic field When a magnetic field is near a wire, activating the field's repelling and attracting qualities, it causes the electrons to flow in a direct current.
What is the term for magnetic strength on a two-dimensional surface? (A) coils (B) magnetic flux (C) magnetic effect (D) electromagnetic induction
B. magnetic flux Magnetic flux is the magnetic strength on a plane, like on one side of a magnet.
What does the U.S. National Electrical Code mandate for color-coded wires? (A) hot wires only (B) neutral and ground wires only (C) hot wires and neutral wires only (D) ground wires only
B. neutral and ground wires only The U.S. National Electrical Code mandates only the neutral wire (white or gray) and the ground (green, green with a yellow stripe, or bare copper). The other wires tend to have common-knowledge use (such as red and black for "hot" wires).
Resistance is the ratio of potential difference across a component to the current passing through it. How is it measured? (A) amps (B) ohms (C) volts (D) degrees
B. ohms The amount of resistance that interferes with the flow is measured in ohms. The symbol used is the Greek letter omega, Ω.
What does the following symbol represent? (A) push switch (B) push-to-break switch (C) on/off switch (D) relay
B. push-to-break switch The symbol represents a push-to-break switch, which, when activated, will power off the circuit.
What process changes incoming alternating current (AC) to direct current (DC)? (A) magnetic effect (B) rectification (C) transformation (D) impedance
B. rectification Rectification occurs in certain electronic circuits that need to change incoming AC to DC in order to run properly.
Frank wanted to set the mood, so he dimmed the lights in his living room. What type of variable resistor did he use? (A) potentiometer (B) rheostat (C) inductor (D) buzzer
B. rheostat A rheostat is a type of variable resistor with two contacts usually used to control current.
What type of circuit has only one possible path for electrical current to flow? (A) parallel (B) series (C) series-parallel (D) complex
B. series A series circuit (perhaps the simplest type of circuit) can follow only one possible path.
What occurs when wires cross, causing the electricity to bypass the intended circuit? (A) explosion (B) short circuit (C) voltage overload (D) watt resistance
B. short circuit A short circuit occurs when electricity bypasses the circuit instead of following the intended path.
What is a circuit? (A) a fancy race (B) the path of a current (C) electric connectors (D) the force of a volt
B. the path of a current A circuit is the path of an electrical current.
What changes resistance according to varying temperatures? (A) diodes (B) thermistors (C) magnetic fluxes (D) transformers
B. thermistors A thermistor is a type of resistor that varies resistance significantly based on surrounding, fluctuating temperatures.
Which of the following common electric symbols is used only once in the diagram? (A) circuit (B) transformer (C) resistor (D) wire
B. transformer This symbol represents a transformer. According to the diagram, there are two circuits connected by one transformer. There are three resistors and many joined wires used to assemble this fluorescent lamp.
What is used to amplify a signal? (A) transformer (B) transistor (C) alternating current (D) remote control
B. transistor A transistor is a semiconductor device used to amplify electronic signals.
What does the following symbol represent? (A) joined wires (B) unjoined wires (C) AC power supply (D) DC power supply
B. unjoined wires The symbol represents unjoined wires in a circuit.
What does every wired device receive after functional tests? (A) packaging (B) voltage rating (C) color code (D) seal of approval
B. voltage rating The standard set by a voltage rating greatly reduces the risk of damage and fire.
In this diagram of a simple circuit, what does the circle with a V symbolize? (A) voltage (B) voltmeter (C) variable resistor (D) variable
B. voltmeter A voltmeter is an instrument used for measuring electrical potential difference between two points in an electrical circuit.
If you use a 40-watt light bulb for three hours, how many watt-hours have you used? (A) 40 (B) 60 (C) 120 (D) 200
C. 120 Watt-hours are measured by multiplying the amount of wattage by the hours used, so 40 × 3 = 120.
How many amplifiers are shown in the following simple circuit? (A) 1 (B) 2 (C) 3 (D) 7
C. 3 This symbol represents an amplifier. The simple differential amplifier circuit contains 3 amplifiers.
5 + 10 + 15 = Solve the equation and choose the best unit of measurement based on the symbol shown in the figure. (A) 30 capacitors (B) 30 volts (C) 30 microfarads (D) 30 electrodes
C. 30 microfarads μF is the symbol for microfarad, which is used to rate capacitors.
9. What does the arrow over the resistor symbol represent? (A) indicator (B) direct current (C) variable (D) live
C. A variable resistor is a potentiometer with two connecting wires instead of three; it allows for finer control over the current by changing the amount of resistance.
8. The amount of electrical power is measured in units called (A) volts. (B) amperes. (C) watts. (D) ohms.
C. A watt measures the amount of power, the rate at which energy is produced or used. The correct answer is Choice (C).
Select the correct answer based on the two diagrams of separate bulbs circuits. (A) Circuit A has more bulbs than Circuit B. (B) Circuit A has brighter bulbs than Circuit B. (C) Circuit B has brighter bulbs than Circuit A. (D) Circuit B has a larger battery than Circuit A.
C. Circuit B has brighter bulbs than Circuit A. When the bulbs are connected in parallel rather than in series, the total resistance in the circuit is lower. Therefore, each bulb in Circuit B receives more current and consumes more power, leading to brighter bulbs.
3. Which of the following has the least resistance? (A) iron (B) rubber (C) copper (D) wood
C. Copper is the best conductor of electricity of those listed here. Therefore, it offers the least resistance to an electric current. The correct answer is Choice (C).
1. What does the abbreviation DC stand for? (A) duplicate charge (B) direct charge (C) direct current (D) diode current
C. DC stands for direct current.
14. What is the term for magnetic effects that are perpendicular to the conductor and parallel to each other? (A) north pole (B) semiconductor (C) lines of force (D) electroplating
C. In a wire, magnetic lines of force are perpendicular to the conductor and parallel to each other.
What does it mean to an electrician if black electrical tape is layered at the end of a neutral wire? (A) It is broken. (B) It is hot. (C) It may conduct electricity. (D) It needs to be replaced.
C. It may conduct electricity. In some cases, a neutral wire may be used as a live wire, so black tape is wrapped around the end to alert electricians that it may be conducting electricity.
Which of the following means "current equals voltage divided by resistance"? (A) Kirchhoff's law (B) power (C) Ohm's law (D) resistance in parallel
C. Ohm's law Ohm's law says , where I is current, V is voltage, and R is resistance. According to this law, the current in a circuit is directly proportional to the applied voltage and inversely proportional to the circuit resistance.
17. What color wire from the following choices is not considered a "hot" wire? (A) red (B) black (C) gray (D) blue
C. Red, black, and blue wires are always "hot" and should never be tampered with unless the power is off. The gray wire is a neutral, Earth-connected wire.
What causes a circuit breaker to trip? (A) You unplug a load from the circuit. (B) You turn on all the lights in the house. (C) The current running through the circuit generates too much heat. (D) The magnetic field is overloaded.
C. The current running through the circuit generates too much heat. Although a circuit breaker can trip for many reasons, ultimately it does so for protection against generated heat from the electrical current.
18. What does the following symbol represent? (A) fuse (B) ground (C) outlet (D) resistor
C. The symbol represents an electrical outlet, which indicates where electronics can be plugged into a circuit.
13. What occurs when a wire is wrapped around an iron core and a current is sent through the wire? (A) chemical effect (B) heat effect (C) magnetic effect (D) physiological effect
C. When a wire is wrapped around an iron core and a current is sent through the wire, the iron becomes magnetized.
What is a potentiometer? (A) a transistor (B) a transformer (C) a variable resistor (D) a magnetic field
C. a variable resistor A potentiometer is a variable resistor with three contacts that are used to control voltage.
According to the diagram, what does the circle with an A symbolize? (A) amplifier (B) antenna (C) ammeter (D) alternating current
C. ammeter Current meters, called ammeters, measure the flow of current through a circuit.
What does the following symbol represent? (A) transistor (B) current (C) amplifier (D) antenna
C. amplifier The symbol represents an amplifier, which is a complex circuit used to magnify power, current, or voltage.
What is the value for black and white in the resistor band color code? (A) black is 1, white is 2 (B) black is 0, white is 1 (C) black is 0, white is 9 (D) black is 1, white is 9
C. black is 0, white is 9 The band code lists black at 0 value and white at 9 value.
What does the following symbol represent? (A) variable capacitor (B) diode (C) buzzer (D) resistor
C. buzzer The symbol represents a buzzer, which is a transducer that converts electrical energy to sound.
Which term refers to the process of finding the voltage across and the current through every component in an electrical circuit? (A) analog circuit (B) electrical circuit (C) circuit analysis (D) circuit integration
C. circuit analysis Circuit analysis is the process of finding the current and voltage of every component in an electrical circuit.
Which of these devices interrupts electrical current? (A) plug (B) transformer (C) circuit breaker (D) diode
C. circuit breaker A circuit breaker automatically interrupts electrical current.
What device compares two voltages or currents and then switches its output to indicate which is larger? (A) voltmeter (B) ammeter (C) comparator (D) transistor
C. comparator Comparators compare voltage or current so a device can determine how much more (or less) is needed to perform a particular function.
What is the purpose of a rectifier? (A) amplifies frequency (B) converts a negative to a positive (C) converts AC to DC (D) measures power
C. converts AC to DC The purpose of a rectifier is to change alternating current (AC) to direct current (DC).
What is the term for the rate of flow of electrons in a conductor? (A) coulomb (B) battery cell (C) electrical current (D) amperes
C. electrical current Coulombs are units of electrical charge, and a battery cell produces a certain electrical voltage. Electrical current is the term used for the rate of flow of electrons in a conductor. Amperes (amps) are the units you use to measure current; an amp equals 1 coulomb per second.
Which of the following is a safety device that melts if a flowing current exceeds a specific value? (A) cell (B) battery (C) fuse (D) transducer
C. fuse A fuse is a safety device that "blows" if the current is too much for the components.
Transistors are usually made of what material? (A) iron (B) silk (C) germanium (D) wood
C. germanium Transistors are usually made of germanium or silicon.
What color wire from the following choices is not considered a "hot" wire? (A) red (B) black (C) gray (D) blue
C. gray Red, black, and blue wires are always "hot" and should never be tampered with unless the power is off. The gray wire is a neutral, earth-connected wire.
What is the term for the part of a circuit that always measures 0 volts? (A) positive terminal (B) negative terminal (C) ground (D) battery
C. ground Ground is any part of a circuit that measures 0 volts.
What does the following symbol represent? (A) conductor (B) volt (C) ground (D) transformer
C. ground The symbol represents ground, which provides a good return path for electrons.
What does the following symbol represent? (A) indicator lamp (B) microphone (C) joined wires (D) inductor
C. joined wires The symbol represents joined wires, which are used to pass current from one part of the circuit to another.
What is the term for magnetic effects that are perpendicular to the conductor and parallel to each other? (A) north pole (B) semiconductor (C) lines of force (D) electroplating
C. lines of force In a wire, magnetic lines of force are perpendicular to the conductor and parallel to each other.
What does the following symbol represent? (A) fuse (B) ground (C) outlet (D) resistor
C. outlet The symbol represents an electrical outlet, which indicates where electronics can be plugged into a circuit.
What does the following symbol represent? (A) potentiometer (B) buzzer (C) rheostat (D) fuse
C. rheostat The symbol represents a rheostat, which is a type of variable resistor that restricts the amount of electrical current.
Divided current in parallel resistors is equal to what? (A) voltage (B) wattage (C) total current (D) total watt-hours
C. total current Voltage is equal between two resistors in parallel, but the current is divided between them. The divided current is equal to the total current.
According to the diagram, what four components make up the circuit? (A) voltmeter, ammeter, fuse, and potentiometer (B) voltmeter, ammeter, ground, and cell (C) voltmeter, ammeter, resistor, and cell (D) voltmeter, ammeter, battery, and capacitor
C. voltmeter, ammeter, resistor, and cell The circuit consists of a voltmeter, an ammeter, a resistor, and a cell.
846- What is the term for the amount of work done per unit charge when electrons move between two points? (A) time (B) regulation (C) volts (D) ohms
C. volts The amount of work done per unit charge when electrons move between two points is measured in volts.
What type of insulator would discourage electric current? (A) copper (B) water (C) wood (D) iron
C. wood Wood is a type of insulator that discourages electrons from moving freely.
How many volts are left after the current makes one loop around the circuit? (A) 9 volts (B) 12 volts (C) 20 volts (D) 0 volts
D. 0 volts Each component in the circuit offers resistance, lowering the amount of voltage as it passes. After the current makes one loop around the circuit, there's no voltage left.
What does a megahertz (MHz) represent? (A) 100 hertz (B) 1,000 hertz (C) 100,000 hertz (D) 1,000,000 hertz
D. 1,000,000 hertz Most electronic devices operate at high frequencies, measured in hertz. A megahertz (MHz) is a measurement of 1,000,000 hertz.
6. A device used to amplify a signal is called a (A) diode. (B) transformer. (C) rectifier. (D) transistor.
D. A diode is a semiconductor that conducts electricity in one direction only; a transformer is a device that changes voltage (either "transforming" low voltage to high voltage or high voltage to low voltage); a rectifier is a circuit that changes alternating current to direct current. Choice (D) is the correct answer.
The following illustration is an example of what? (A) transformer (B) diode (C) transistor (D) circuit
D. Circuit A circuit is a closed path followed or capable of being followed by an electric current.
2.Ohm symbol?
D. Remember, the upside-down horseshoe (the Greek letter omega) is the symbol for ohm, the measure of electrical resistance.
Which of the following is a silvery, highly reactive metallic element that is used as a heat transfer medium? (A) mercury (B) iron (C) lithium (D) all of the above
D. all of the above Any metal can be a conductor of heat and electricity. All of the ones listed are silvery and highly reactive conductors.
What do the color codes on resistors indicate? (A) value (B) tolerance (C) quality (D) all of the above
D. all of the above The first two colors indicate the first two digits of the value, while the third represents the number of zeros. A gold or silver indicates tolerance, while anything following would represent quality.
How can you increase magnetic field strength in a coil? (A) increase the number of coils (B) increase the amount of current (C) condense the coils (D) all of the above
D. all of the above You can increase magnetic field strength in a coil by increasing the number of coils, the number of turns, and the amount of current.
What are amplifier circuits used to magnify? (A) current (B) voltage (C) power (D) all of the above
D. all of the above An amplifier is a complex circuit used to magnify current, voltage, and power.
What measures the flow of current through a circuit? (A) amperes (B) coulombs (C) milliamperes (D) ammeters
D. ammeters Ammeters, or current meters, measure the flow of current through a circuit.
What does the following symbol represent? (A) wire (B) cell (C) diode (D) antenna
D. antenna The symbol represents an antenna, which is a device designed to receive or transmit radio signals.
Which term refers to the process of electrons moving from one place to another? (A) gravity (B) force (C) exertion (D) electric current
D. electric current An electric current occurs when electrons move from one place to another.
What color wire is not used for any other purpose than grounding to the Earth? (A) red (B) white (C) black (D) green
D. green A green-colored wire signifies that it's a protective ground wire.
In what electrical object would a filament be found? (A) oven (B) clothes iron (C) computer (D) lamp
D. lamp A filament is the fine wire heated electrically to incandescence in an electric lamp.
What can be used to increase or decrease electrical voltage? (A) accelerator (B) electrical pole (C) ignitron (D) transformer
D. transformer A transformer transfers electrical voltage from one place to another in increasing or decreasing amounts, as needed.
How is power measured? (A) diodes (B) degrees (C) volts (D) watts
D. watts Power is measured in watts.
15. What symbol is not shown in the following circuit diagram? (A) transformer (B) fuse (C) resistor (D) transistor
Next one has the answer with another image to compare
Current: Amperes (or amps) Voltage: Volts Resistance: Ohms Power: Watts Energy: Watt-hours
Ohms law Current = Voltage / Resistance or P=EI Current flows from a negative pole to a positive pole. A closed circuit must exist for electricity to flow. (Think NASCAR.) Alternating current (AC) changes direction constantly at a constant rate. The number of times a current completes two alternations of direction per second is known as its frequency; the unit of measurement Electronic devices operate at very high frequencies. Electronic devices often require a specific capacitive or inductive reactance to work. Capacitors and inductors are devices used in circuits to provide the type of reactance needed. Devices that change alternating current to direct current are called rectifiers. A transistor can amplify a signal.
What has two components commonly known as an element and a wiper? (A) variable resistor (B) integrated circuit (C) magnetic encoders (D) basic electrode
A. variable resistor A variable resistor, such as a radio tuner, has an element that provides resistance and a movable component called a wiper that sets the resistance.
How many ohms are measured in this simple circuit? (A) 9 (B) 900 (C) 100 (D) 50
C. 100 There are 100 ohms in this simple circuit. The symbol for ohms is Ω, and ohms measure resistance.
What does the arrow over the resistor symbol represent? (A) indicator (B) direct current (C) variable (D) live
C. variable A variable resistor is a potentiometer with two connecting wires instead of three; it allows for finer control over the current by changing the amount of resistance.
What is another word for electromotive force? (A) frequency (B) heat (C) voltage (D) ohms
C. voltage Voltage is another word for electromotive force.
What does the following schematic represent? (A) railroad tracks (B) engine wiring (C) radio wiring (D) lighting system
D. lighting system This schematic is a closed circuit that includes a battery and three indicator lamps.
What transducer converts electrical energy to kinetic energy? (A) heater (B) buzzer (C) microphone (D) motor
D. motor If you know kinetic energy is linked to motion, you can correctly choose Choice (D), motor.
What effect occurs when electricity contracts human muscle tissue? (A) chemical effect (B) heat effect (C) magnetic effect (D) physiological effect
D. physiological effect Current produces this effect when it passes through a muscle and causes it to contract.
What is the name of an object that conducts electricity poorly at low temperatures? (A) magnifier (B) terminal (C) coulomb (D) semiconductor
D. semiconductor A semiconductor is a complex device, usually made of silicon, that is often found in small electronics, such as cellphones. A semiconductor conducts more electricity than an insulator but less than aluminum and copper.
What does an ohm measure? (A) resistance (B) force (C) heat (D) time
The ohm measures resistance, including anything that could limit the flow of electrons. A. resistance
Answer for # 15
This symbol represents a fuse; the circuit doesn't contain a fuse.