DesignEngineering–EA1.3Electronics
ProblemSheet1(Lectures1,2&3)
Key:[A]=easy……[E]=hard
1. [A]Oneofthefollowingcircuitsisaseriescircuitandtheotherisaparallelcircuit.Explain
whichiswhich.
2. [B]FindthepowerabsorbedbybyeachofthesubcircuitsAandBgiventhatthevoltage
andcurrentare10Vand2Aasshown.
3. [B]Foreachofthefourcircuitsbelow,findthepowerabsorbedbythevoltagesource(PV),
thepowerabsorbedbythecurrentsource(PI)andthetotalpowerabsorbed(PV+PI).
4. [B]DeterminethevoltageVXinthefollowingcircuit.
5. [B]DeterminethecurrentIXinthefollowingcircuit.
6. [B]Whatsingleresistorisequivalenttothethree-resistorssub-circuitshownbelow?
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7. [B]Whatsingleresistorisequivalenttothethree-resistorssub-circuitshownbelow?
8. [C]Whatsingleresistorisequivalenttothefive-resistorssub-circuitshownbelow?
9. [A]Ifaresistorhasaconductanceof8µS,whatisitsresistance?
10. [B]Determinethevoltageacrosseachoftheresistorsinthefollowingcircuitandthepower
dissipatedineachofthem.Calculatethepowersuppliedbythevoltagesource.
11. [B]Determinethecurrentthrougheachoftheresistorsinthefollowingcircuitandthe
powerdissipatedineachofthem.Calculatethepowersuppliedbythecurrentsource.
12. [B]DetermineR1sothatY=(1/4)X.
13. [B]ChooseR1andR2sothatY=0:1XandR1+R2=10MΩ.
14. [D]Youhaveasupplyofresistorsthathavethevalues{10;12;15;18;22;27;33;39;47;56;
n
68;82}x10 Ωforallintegervaluesofn.Thus,forexample,aresistorof390Ωisavailable
andthenexthighervalueis470Ω.Showhow,bycombiningtworesistorsineachcase,itis
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possibletomakenetworkswhoseequivalentresistanceis(a)3kΩ,(b)4kΩand(c)asclose
aspossibleto3.5kΩ.Determinetheworst-casepercentageerrorthatmightariseif,instead
ofcombiningresistors,youjustpicktheclosestoneavailable.
15. [A]GiventwoswitchesAandB,designaconfigurationwhichgivesaTRUEoutputonly
whenAandBarebothclosed.Includeanynecessaryconnectionstoa5Voltpowersupply,
showatwhichpointinthecircuityouwouldmeasuretheoutputvoltageanddescribethe
relationshipbetweenthevoltagemeasuredandthelogicalvalues.
16. [A]Howmanydifferentsymbolscanberepresentedwith4bits?
17. [A]Convertthefollowingdecimalnumbersintobinary.Donotuseacalculator.
a) 5
b) 99
c) 1024
18. [A]Convertthefollowingbinarynumbersintodecimal.Donotuseacalculator.
a)1010
b)10000000 c)11111111
19. [B]Convertthefollowingdecimalnumbersintohexadecimal.Donotuseacalculator.
a) 64
b) 98
20. [B]Convertthefollowinghexnumbersintobinarydirectlywithoutfirstconverting them
to decimal. Do not use a calculator.
a) F8
b) 144
21. [B]Performthefollowingbinaryarithmetic:
a) 00110111 + 00110010
c) 00110100 - 00001010
b) 1100 + 0100
d) 0010 – 0111
22. [B]Inadatatransmissionsystemthesetofpossiblesymbolsis:
{lower-casealphabet}U{upper-casealphabet}U{space,comma,full-stop}
where'U'denotesthe'union'oftwosets.Howmanybitsofinformationareneededfor
eachsymbol?
23. [D]Intheabovedatatransmissionsystemthemaximumtransmissionrateis9600bitsper
second.Howlong,inseconds,wouldittaketotransmitthemessage:ImperialCollege.
24. [C]Convertthestring“ImperialCollege”intoASCIIcode.Howmanybytesareneeded to
store such a string?
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