voltage and current

Voltage and current------------------- general questions------------------1.What is the color code for a 220 5% resistor?

A.Red, Red, Brown, Gold

B.Orange, Orange, Black, Gold

C.Red, Red, Black, Gold

D.Red, Red, Brown, Silver

Answer & ExplanationAnswer: Option AExplanation:Resistor colour coding series:

Black 0 Brown 1 Red 2 Orange 3 Yellow 4 Green 5 Blue 6 Violet 7 Gray 8 White 9 None 20% Silver 10% Gold 5%

Therefore Red, Red, Brown, Gold 2 2 101 5%

= 22 x 10 = 220 ohm 5% (tolerance).

2.If 60 J of energy are available for every 15 C of charge, what is the voltage?

A.4 V

B.60 V

C.15 V

D.0.25 V

Answer & ExplanationAnswer: Option A

3.An atom's atomic number is determined by the number of:

A.neutrons minus protons

B.protons

C.electrons

D.neutrons

Answer & ExplanationAnswer: Option B

4.A voltage will influence current only if the circuit is:

A.open

B.insulated

C.high resistance

D.closed

Answer & ExplanationAnswer: Option D

5.Which resistive component is designed to be temperature sensitive?

A.Thermistor

B.Rheostat

C.Potentiometer

D.Photoconductive cell


6.The battery symbol is:

A.

B.

C.

D.


7.What type of switch is this?

A.push button

B.SPST

C.DPDT

D.SPDT


8.Primary batteries, unlike secondary batteries, may be:

A.charged once

B.used once

C.recharged over and over

D.stored indefinitely

Answer & ExplanationAnswer: Option BExplanation:Primary batteries (disposable batteries), which are designed to be used once and discarded when they are exhausted.

Secondary batteries (rechargeable batteries), which are designed to be recharged and used multiple times.

9.In practical applications, battery voltage:

A.is restored as soon as disconnect occurs

B.is lowered as the load increases

C.may be stored indefinitely

D.will be reduced to zero as power is drawn


10.The negative and positive charge symbols are assigned (in that order) to the:

A.proton and electron

B.electron and proton

C.atom and nucleus

D.electron and element


11.A voltmeter is used:

A.to measure current

B.in series with the circuit

C.in parallel with the circuit

D.to measure coulombs

Answer & ExplanationAnswer: Option C

12.If the current in a circuit equals 0 A, it is likely that the

A.voltage is too high

B.resistance is too low

C.circuit has a short

D.circuit is open


13.Current equals:

A.

B.coulombs time

C.

D.voltage time


14.What are the unit and symbol for current?

A.Ampere, A

B.Coulomb, I

C.Ampere, Q

D.Ampere, I


15.Which part of an atom has no electrical charge?

A.Electron

B.Neutron

C.Proton

D.All of the above


16.Which voltage source converts chemical energy to electrical energy?

A.Electrical generator

B.Battery

C.Solar cell

D.Electronic power supply


17.An example of potential energy is:

A.tea-kettle steam

B.a moving vehicle

C.the sun

D.a battery


18.If 40 C of charge flow past a point in 20 s, what is the current?

A.2 AB.0.5 A

C.20 AD.40 A


19.Batteries differ from fuel cells in that

A.a battery is a closed system

B.a battery uses hydrogen and oxygen to create electricity

C.a battery uses a polymer electrolyte membrane

D.none of the above


20.The removal of a non-neutral subatomic particle converts the atom into a:

A.charged ion

B.nucleus

C.heavier element

D.compound


21.One coulomb passing a point in one second is one:

A.ampereB.volt

C.ohmD.charge


22.In which states may matter may be found?

A.solid, liquid, or mineral

B.solid, gas, or liquid

C.mineral, gas, or liquid

D.plastic, solid, or gas


23.Material that consists of a mixture of elements is considered to be:

A.an elementB.an ion

C.a compoundD.a molecule


24.How many valence shell electrons are there in semiconductor atoms?

A.16B.8

C.4D.2


25.When considering conventional current versus electron current flow:

A.electron current flow came first

B.protons move in conventional current flow

C.conventional current flow came first

D.the direction of current is the same in both methods


26.Which unit of charge contains 6.25 1018 electrons?

A.An ampereB.A coulomb

C.A voltD.A joule


27.A switch is a device that:

A.short circuits complex circuits

B.holds a fuse

C.has double poles

D.opens or completes a current path


28.The term used to designate electrical pressure is:

A.voltageB.current

C.resistanceD.conductance


29.Which electronics material opposes the movement of free electrons?

A.ConductorB.Insulator

C.SemiconductorD.Element


30.Current is considered as the movement of:

A.electronsB.protons

C.chargeD.nuclei


31.A lead-acid battery is an example of a

A.solar cell

B.fuel cell

C.primary battery

D.secondary battery


32.The charge of one coulomb is equal to:

A.6.24 x 1018 electrons

B.one ampere

C.one second

D.6.24 x 1018 electrons


33.A basic electric circuit is made up of what components?

A.A load, a resistor, and a conductive path for current

B.A voltage source, a load, and a conductive path for current

C.A voltage source, a conductive path for current, and a battery

D.A conductive path for current, a battery, and a copper wire


34.An ammeter is used to measure

A.voltageB.current

C.resistanceD.All of the above


35.What is the name of the pressure that moves electrons in a closed circuit?

A.amperesB.ohms

C.voltageD.coulombs


36.What is a characteristic of a secondary cell?

A.rechargeability

B.not rechargeable

C.a dry cell

D.non-liquid


37.What are the basic building blocks that all matter is composed of?

A.electrons, neutrons, and protons

B.two protons for each neutron

C.two protons for each electron

D.electrons, neutrons, and charged ions


38.If a fluid system is compared to an electrical system, the fluid pump will correspond to a:

A.conductorB.lamp

C.batteryD.insulator


39.An element is a substance that is:

A.varied throughout the entire piece

B.used only in electronics

C.electrically charged

D.found only in its pure form


40.Current is:

A.the presence of a positive charge

B.the abundance of electrons

C.the movement of electrons

D.the repulsion of electrons


41.What do you call a diagram that shows the electrical connections of a circuit's components?

A.A schematic diagram

B.A pictorial diagram

C.A block diagram

D.An electrical diagram


42.A short circuit will have:

A.a small current flow

B.a large current flow

C.no current flow

D.some current flow


43.The basic difference between a fuse and a circuit breaker is

A.a fuse is slower

B.a fuse is reusable

C.a circuit breaker is reusable

D.a circuit breaker is more reliable


44.Which is the smallest?

A.atomB.proton

C.neutronD.electron


45.A secondary cell generates dc via chemical activity; a primary cell generates dc:

A.electricallyB.thermally

C.opticallyD.chemically


46.Which of the following statements is true?

A.Unlike charges repel and like charges attract.

B.Like charges repel and unlike charges attract.

C.Unlike charges attract and like charges attract.

D.Like charges repel and unlike charges repel.


47.If an electrical system is compared to a fluid system, the electrical current corresponds to the:

A.pressureB.pump

C.water wheelD.water flow


True and false1.The shell that is closest to the nucleus of an atom can contain a maximum of two electrons.

A.TrueB.False


2.One coulomb of charge passing a point in one second is one ampere of current.

A.TrueB.False


3.The unit of measurement for conductance is the coulomb.

A.TrueB.False

Answer & ExplanationAnswer: Option BExplanation:The siemens (symbol: S) is the SI derived unit of electric conductance and electric admittance. Conductance and admittance are the reciprocals of resistance and impedance respectively, hence one siemens is equal to the reciprocal of one ohm, and is sometimes referred to as the mho.

4.An electron is the smallest subatomic particle of negative charge that orbits the nucleus of the atom.

A.TrueB.False


5.A multimeter measures only voltage.

A.TrueB.False


6.In the eighteenth and nineteenth centuries conventional current flow was routinely used.

A.TrueB.False


7.Voltage is the driving force that establishes the flow of current.

A.TrueB.False


8.A resistor color coded with brown, black, and orange bands has a value of 10 k.

A.TrueB.False


9.A conductor will not carry current.

A.TrueB.False


10.The abundance of electrons would imply a negative charge.

A.TrueB.False


11.The atomic number is the number of neutrons in the nucleus of an atom.

A.TrueB.False


12.Charges of the same polarity tend to attract one another.

A.TrueB.False


13.The atomic number of an atom equals the number of electrons orbiting the nucleus.

A.TrueB.False

Answer & ExplanationAnswer: Option BExplanation:In chemistry and physics, the atomic number (also known as the proton number) is the number of protons found in the nucleus of an atom and therefore identical to the charge number of the nucleus.

14.A normally open push-button switch can carry current when not pushed.

A.TrueB.False


15.Switches are either on or off, but can have multiple poles.

A.TrueB.False


16.The movement of electrons between two points is called voltage.

A.TrueB.False


17.Electrons flow from negative to positive when a voltage is applied across a conductor.

A.TrueB.False


18.The symbol that represents electrical charge is Q.

A.TrueB.False


19.All conductors have some resistance.

A.TrueB.False


20.Resistance is the pressure that causes current to flow.

A.TrueB.False


21.The potential difference between two points is called voltage.

A.TrueB.False


22.An open circuit allows current to flow.

A.TrueB.False


23.Switches are used to open and close paths for current.

A.TrueB.False


24.Carbon is a semiconductor.

A.TrueB.False


Fill in the blanks-----1.The unit for voltage is the ___ and the symbol for voltage is ___.

A.joule, VB.coulomb, J

C.volt, QD.volt, V


2.A connection to the frame of a piece of electronic equipment is sometimes referred to as ___ ground.

A.a chassis

B.an earth

C.a circuit

D.either chassis or circuit


3.Fuses and circuit breakers are designed to ___ when excessive current flows.

A.buzzB.illuminate

C.closeD.open


4.The capacity of a battery cell is measured by the amount of __________ that can be supplied over time.

A.currentB.voltage

C.coulombsD.joules


5.A rheostat is ___.

A.a three-terminal device that controls current

B.a two-terminal device that controls current

C.a two-terminal device that divides voltage

D.a three-terminal device that divides voltage


6.If an electronic component fails by developing an open circuit, the current will __________.

A.increaseB.decrease

C.ceaseD.not change


7.___ make electric current possible.

A.ProtonsB.Neutrons

C.ShellsD.Free electrons


8.The ___ is placed in series with the flow of current.

A.voltmeterB.ammeter

C.ohmmeterD.wattmeter


9.The ___ represents a negative charge in an atom.

A.electronB.proton

C.neutronD.None of the above


10.An atom of a semiconductor has _______________ electrons in the valence shell.

A.4B.8

C.2D.0


11.An atom with more electrons than protons is ___.

A.a positive ion

B.a balanced atom

C.a negative ion

D.not possible


12.All resistors can be placed into one of two main categories: ___ or ___.

A.carbon film, metal film

B.fixed, variable

C.wire wound, carbon-composition

D.insulator, semiconductor


13.Voltage is _________.

A.the opposition to the flow of current

B.the movement of free electrons

C.the force that exists between charged particles

D.the force that causes water to flow


14.A ___ resistor has color bands of yellow, violet, yellow, gold.

A.470 5%

B.5.7 M 5%

C.37 k 5%

D.470 k 5%


15.The unit for resistance is the ___ and the symbol for resistance is ___.

A.ampere, RB.ohm, R

C.volt, QD.ohm, J


voltage and current

Documents