Electronics Information
B
The symbol below represents a ___, which supplies electrical energy (A) Junction (B) Cell (C) Diode (D) Plug
C
The symbol for inductance is (A) X(sub)L (B) I (C) L (D) X(sub)C
C
The symbols below (left to right) represent an ___, ___, ___, and ___. (A) Ammeter, potentiometer, oscilloscope, voltmeter (B) Ampmeter, potentiometer, ohmmeter, voltmeter (C) Ammeter, galvanometer, ohmmeter, voltmeter (D) Ammeter, oscilliscope, ohmmeter, voltmeter
B
The symbols below represent a (A) Thyristor (B) Resistor (C) Transistor (D) Fuse
A
The symbols below represent different types of (A) Switches (B) Inductors (C) Transistors (D) Transformers
Which of the following instruments is used to measure resistance of a load? a.)Voltmeter b.)Ohmmeter c.)Ammeter d.)Galvanometer
b.)Ohmmeter
B
A 12-volt battery contains how many cells (A) 1 (B) 6 (C) 8 (D) 9
B
A 120-volt circuit has resistance 6 ohms. How much current is present in the circuit? (A) 0.2 amperes (B) 20 amperes (C) 40 amperes (D) 720 amperes
C
A capacitor of 100 microfarads has a capacity of (A) 100 picofarads (B) 10 picofarads (C) 100,000,000 picofarads (D) 10,000 picofarads
B
A carbon resistor marked with colored bands of (left to right) red, brown, orange, and gold is what value and tolerance? (A) 2,100 ohms ±5% (B) 21,000 ohms ±5% (C) 21 ohms ±5% (D) 210 ohms ±5%
A
A conductor is any material that (A) Has many free electrons (B) Has no free electrons (C) Has free ions (D) Has free protons
B
A junction diode is used for (A) Rectifying power-line frequencies and lower currents (B) Rectifying power-line frequencies and higher currents (C) Rectifying higher frequencies at lower currents (D) Rectifying higher frequencies at higher currents
C
A resistor marked "2kΩ" has a value of (A) 1.5 ohms (B) 200 ohms (C) 2,000 ohms (D) 2,000 watts
C
A signal's frequency is inversely proportional to its (A) Amplitude (B) Phase (C) Period (D) Oscillation
D
A watt is the power that gives rise to the production of energy at a rate of (A) 1 joule per minute (B) 1 volt per second (C) 1 amp per second (D) 1 joules per second
B
An ampere (or "amp" for short) is defined as (A) An electrical flow of 100 volts per second (B) An electrical flow of one coulomb per second (C) The strength of a magnetic field through a capacitor (D) A measurement of the ion flow from a power source
B
An oscillator is (A) A device that measures the waves of varying electrical signals (B) An electronic circuit that produces a regularly varying electrical signal from a direct current (C) A device that performs mathematical operations using an analog signal (D) A device that keeps output voltage from oscillating beyond a desired level
b.) Semiconductor
Another name for a transistor is (A) Integrated circuit (B) Semiconductor (C) Transfer resistor (D) Pettigrew connector
B
The symbol below represents a (A) Potentiometer (B) Capacitor (C) Battery (D) Transducer
B
The symbol below represents a (A) Triode (B) Light emitting diode (LED) (C) Transducer (D) Light sensitive diode
C
Capacitors connected in series obtain a resulting value (A) Greater than the sum of the individual capacitor values (B) Equal to the sum of the individual capacitor values (C) Less than that of the smallest capacitance (D) Produces neutral change in capacitance values
C
Conventional current flow is from (A) + to + (B) - to + (C) + to - (D) - to -
C
Current that changes polarity many times per second is called (A) Direct current (B) Reciprocating current (C) Alternating current (D) AC/DC current
D
The parallel circuit with resistors of 10 ohms, 10 ohms, and 5 ohms has a total resistance of (A) 10 ohms (B) 5 ohms (C) 25 ohms (D) 2.5 ohms
B
Electricity is defined as the flow of ___ along a ___ (A) electrons, resistor (B) electrons, conductor (C) positrons, conductor (D) neutrons, pathway
C
The property of a circuit that opposes the flow of electrons is (A) Reactance (B) Capacitance (C) Resistance (D) Inductance
A
The symbol below represents a (A) Diode (B) Triode (C) Transducer (D) Switch
B
Inductive resistance is found by using the formula (A) X(sub)L = 2(pi)FC (B) X(sub)L = 2(pi)FL (C) X(sub)L = R (D) X(sub)L = Z
B
Resistance in a circuit is changed from 50 ohms to 25 ohms. If the voltage in the circuit remains the same, what will happen to the current? (A) The current will stay the same (B) The current will double (C) The current will decrease by half (D) Not enough information to tell
C
The Greek letter phi (Φ) is used to (A) Indicate ohms (B) Indicate volts (C) Indicate angles or phases (D) Indicate dielectric flux
C
The best reason to use a filter in a power supply is to (A) Convert alternating current to direct current (B) Change direct current to alternating current (C) Even out voltage variations (D) Smooth out power surges
A
The instrument used to measure electrical resistance is called (A) An ohmmeter (B) An ammeter (C) A voltmeter (D) A wattmeter
b.)the flashbulb is turned off
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
c.)variable
What does the arrow over the resistor symbol represent? a.)indicator b.)direct current c.)variable d.)live
b.)Rheostat
What does the following image represent? a.)Fixed Resistor b.)Rheostat c.)Capacitor d.)Potentiometer
c.)outlet
What does the following symbol represent? a.)fuse b.)ground c.)outlet d.)resistor
B
What is an amplifier? (A) A device that makes audio signals reach farther (B) A device that makes sounds louder by increasing signal strength (C) A device that has extra capacitors to increase amperage (D) A device that increases sound fidelity by decreasing resistance
C
What is the total resistance in this circuit if all resistors are 300 ohms? (A) 900 watts (B) 1,200 ohms (C) 900 ohms (D) 600 ohms
a.)ohm
What symbol is this? a.)ohm b.)fuse c.)outlet d.)resistor
b.)fuse
What's missing in this circuit diagram? a.)transformer b.)fuse c.)resistor d.)transistor
B
When the secondary side of a transformer has more turns than the primary side, the output voltage will be ___ the input voltage. (A) Lower than (B) Higher than (C) The same as (D) The square root of
How many valence electrons are present in most semi-conductor materials? a.)4 b.)5 c.)6 d.)7
a.)4
A ground is not one of the following. a.)A place with a maximum resistance. b.)A place of lowest potential in a circuit. c.)A reference point in the circuit from which voltages are measured. d.)A common return path for electric current.
a.)A place with a maximum resistance. *A ground is also called the earth in an electrical circuit. A ground is a place of lowest potential and least resistance in an electrical circuit. Ground/Earth is also a reference point in an electrical circuit from which voltages are measured and a common reference path for electric current.
Which of the following statements is correct? a.)Conventional current flows from positive terminal of the source to its negative terminal through the circuit. b.)Electron current flows from positive terminal of the source to its negative terminal through the circuit. c.)Conventional current flows from negative terminal of the source to its positive terminal through the circuit. d.)Both option A and B
a.)Conventional current flows from positive terminal of the source to its negative terminal through the circuit. *Electron flow is the flow of electrons which actually occurs in a circuit. The electron current flows out of the negative terminal of the source through the circuit to its negative terminal. The conventional current was chosen as a convention at the time of discovery of electric currents, it assumes that the flow of current is out of the positive terminal of the source through the circuit to its negative terminal.
Components designed to store electrical charge are a.)capacitors b.)transformers c.)resistors d.)transistors
a.)capacitors
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
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
Which of the following is true regarding an AC signal? a.)The greater the time period, the greater the frequency. b.)The smaller the time period, the greater the frequency. c.)The time period of an AC signal is directly proportional to the square of the frequency. d.)There is no relation between the frequency and time period of an AC signal.
b.)The smaller the time period, the greater the frequency. *Frequency is the number of occurrences of an event per unit time. The relationship between the frequency and time period of an AC signal is f=1/T i.e. frequency is inversely proportional to the time period of an AC signal. The smaller the time period, the greater the frequency of the signal.
Four bulbs are connected in a series-parallel circuit as shown in the given figure. Each bulb is exhibiting a resistance of 4 ohms. If one of two bulbs in the parallel connection blows up, then what will the effect be on the total effective resistance offered by all the bulbs? a.)The total effective resistance will decrease. b.)The total effective resistance will increase. c.)The total effective resistance will remain same. d.)The circuit would be open.
b.)The total effective resistance will increase. *The resistances are added in series. The equivalent resistance offered by two bulbs in parallel connection would be ((1/4)+(1/4))^-1 = 2. The effective resistance offered by all the four bulbs in this case is 4+2+4 = 10 ohms. If one of the bulbs in parallel connected blows up then the effective resistance offered by all four bulbs would be 4+4+4=12 ohms. Therefore, the effective resistance will increase.
Which of the following statements is incorrect regarding Ohm's Law? a.)Voltage is directly propertional to the current. b.)Voltage is inversely proportional to the resistance. c.)Current is inversely proportional to the resistance. d.)Voltage is directly proportional to both current and resistance.
b.)Voltage is inversely proportional to the resistance.
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.)dot
What process changes incoming alternating current(AC) to direct current(DC)? a.)magnetic effect b.)rectification c.)transformation d.)impedance
b.)rectification
A device used to amplify a signal is called a a.)diode b.)transformer c.)rectifier d.)transistor
b.)transformer
What is the point at which electrical connections(such as two wires) are made? a.)terminal b.)trigger c.)transmitter d.)transformer
b.)trigger
What measures the difference of potential between two points? a.)mechanical advantage b.)volts c.)watt d.)current
b.)volts
A microwave is consuming 800 W power using a standard North American 120 V power supply. What is the approximate amount of current flowing? a.)3 amperes b.)5 amperes c.)7 amperes d.)9 amperes
c.)7 amperes *The formula for finding electrical power is Power = Voltage x Currerent or P=VI. Rearranged we have I = P/V = 800/120 = 6.67 = 7 amperes
A circuit breaker is better than a fuse because a.)Circuit breakers are less expensive. b.)A circuit breaker responds more quickly to an excessive current than a fuse. c.)A circuit breaker can be reused multiple times. d.)A circuit breaker is often not compatible with modern electric equipment.
c.)A circuit breaker can be reused multiple times. *A circuit breaker is better than a fuse because it can be reused multiple times unlike a fuse which needs to be replaced once it is blown.
What measures the number of electrons that move past a specific point in 1 second? a.)voltage b.)current c.)amperes d.)watt
c.)amperes
Which of the following has the best resistance? a.)iron b.)rubber c.)copper d.)wood
c.)copper
What does the abbreviation DC stand for? a.)duplicate charge b.)direct charge c.)direct current d.)diode current
c.)direct current
What color wire from the following choices is not consider a "hot" wire? a.)red b.)black c.)gray d.)blue
c.)gray
What is the term for magnetic effect 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
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.)magnetic effect
What measures resistance including anything that could limit the flow of electrons? a.)coulomb b.)watt c.)ohms d.)current
c.)ohms
The amount of electrical power is measured in units called a.)volts b.)amperes c.)watts d.)ohms
c.)watts
Which of the following is a unit of power? a.)J/s b.)W c.)V.A d.)All of the above
d.)All of the above *Power is the rate of doing work i.e. Power = Work/time = J/s. Electrical power is described as P=VI and the unit of power is Watt (W). Power is the product of current and voltage, so it can also be written as V.A where V represents the voltage and A represents the current.
A capacitor blocks Direct Current (D.C). Hence, it is also known as a: a.)Blocking Capacitor b.)Switched Capacitor c.)Coupling Capacitor d.)Both Blocking and Coupling Capacitors
d.)Both Blocking and Coupling Capacitors *A blocking capacitor is also called the coupling capacitor. It is used to block the passage of flow of direct current (D.C) from one circuit to another by giving alternative passage to flow.
If three different resistors are connected in parallel and a voltage is applied across them, which of the following statements is correct? a.)The smallest resistance has the least power loss across three resistances. b.)The greatest resistance has the maximum power loss across three resistances. c.)Both the smallest and the greatest resistances have the same power losses. d.)The greatest resistance has the least power loss across three resistances.
d.)The greatest resistance has the least power loss across three resistances. *If three different resistances are connected in parallel and a voltage is applied across them then the voltage is same across all the resistances. The formula for finding power is P = VI = V(V/R) = (V^2/R). According to the formula, the resistor with the least value will have the maximum power loss and the resistor with the maximum value will have the least power loss.