GCSE OCR COMPUTER SCIENCE -
PAPER 1 QUESTIONS AND CORRECT
ANSWER
Name bsome bof bthe bjobs bgeneral bpurpose bcomputers bcan bdo b- bcorrect banswer✔✔-
bAccess bthe binternet b
- bUse bword bprocessing b
- bPlay bgames b
- bCommunicate bvia bemail/social bmedia b
- bStore band bretrieve bdata b
- bPlay bmusic
What bis ba bgeneral bpurpose bcomputer? b- bcorrect banswer✔✔A bcomputer bdesigned
bto bcarry bout ba bwide brange bof btasks, bfor bexample, ba btablet, bPC, blaptop bor bsmart
bwatch.
What bis ban bembedded bsystem? b- bcorrect banswer✔✔A bsmall bcomputer bthat bforms
bpart bof ba blarger bsystem, bdevice bor bmachine. bIts bpurpose bis bto bcontrol bthe bdevice
band ballow ba buser bto binteract bwith bit, bhave ba bprocessor band bhave binputs band
boutputs. bThey bhave ba blimited bnumber bof btasks bthat bare bspecific bto bits bfunction,
band bare bnot busually bprogrammable bby ba buser
Give bexamples bof bembedded bsystems b- bcorrect banswer✔✔Fitness btrackers, bsmart
bfridges, bcentral bheating bsystems
Advantages bof bembedded bsystems? b- bcorrect banswer✔✔- bTheir blimited bfunctions
bmean bthey bare bcheaper bto bdesign band bbuild
- bThey btend bto brequire bless bpower b(some bdevices brun bfrom bbatteries b
- bThey bdo bnot bneed bmuch bprocessing bpower, bso bthey bcan bbe bbuild bfrom
bcheaper, bpowerful bprocessers b
- bThe bsoftware bin ban bembedded bsystem bcan bbe bupgraded
What bare bcome bcharacteristics bof bembedded bsystems? b- bcorrect banswer✔✔- bLow
bpower bconsumption
- bSmall bsize
- bLow bcost bper bunit
- bRugged boperating branges
,- bNot busually bprogrammable bby bthe buser, bas bthe bprogramming bhas balready bbeen
bdone bby bthe bmanufacturer, bstored bin bROM bchips
In bwhat bways bis ba bwashing bmachine ban bembedded bsystem? b- bcorrect
banswer✔✔It bhas bembedded bsystems bbecause bit bhas ba bCPU bthat bcan bfunction
blike ba bcomputer, bbut bthese bcomputers bare bspecialised bto bdo btheir bspecific btask.
bEmbedded bsystems bare bspecial bcomputers binside ba blarger bdevice. bIts bpurpose bis
bto bcontrol bthe bdevice b(the bwashing bmachine) bas ballows bit bto binteract band breceive
binputs bfrom bits buser. bEmbedded bsystems bare balways ba bcomputer bin ba blarger
bdevice. bThe binput binto ban bembedded bsystem bof ba bwashing bmachine bcan bbe btype
bof bwashing bcycle bthe buser bchooses, bbuttons band bdials bto badjust btemperature band
bthe boutput bcan bbe bwhen bthe bwashing bfinishes, bsounds band blights. bIt bis bsaved bto
bROM bchips bin bthe bcomputer.
What bbasic bmodels bdo ball bgeneral bpurpose bcomputers bfollow? b- bcorrect
banswer✔✔The bgeneral bpurpose bmodel:
- bData bis binput, band bthen beither boutput bor bsent bto bsecondary bstorage bafter bbeing
bprocessed. bIt bis bheld bis bprimary bmemory bwhile bbeing bprocessed
What bare binput bdevices? b- bcorrect banswer✔✔- bA bdevice bused bto benter bdata bor
binformation binto ba bcomputer b(e.g. ba bmouse, bkeyboard, bscanner bor bmicrophone)
What bare boutput bdevices? b- bcorrect banswer✔✔- bA bdevice bused bto breturn
binformation bfrom ba bcomputer, be.g. ba bmonitor, bprinter bor bspeaker
What bhappens bwith binputs band boutputs bin ba bcomputer? b- bcorrect banswer✔✔The
bCPU breceives bdata band binstructions bfrom ban binput bor bmemory. bThe bins
What bis bhardware band bsoftware? b- bcorrect banswer✔✔Hardware b= bphysical
bcomponents bof bthe bcomputer be.g. bCPU, bhard bdisk, bmonitor b
Software= bPrograms bthat brun bon ba bcomputer
What bare bperipherals? b- bcorrect banswer✔✔Pieces bof bhardware bthat bconnect bto ba
bcomputer band bare badded bto ba bcomputer bto bexpand bits babilities be.g. bmouse,
bkeyboard, bprinter, bscanner. bThey bare binput/output bdevices
What bis bthe bpurpose bof bthe bCPU b- bcorrect banswer✔✔(Central bprocessing bunit)
- bTo bprocess bdata band binstructions bby bcarrying bout bthe bfetch, bdecode bexecute
bcycle b
- bThe bbrain bof bthe bcomputer b- btakes ban binput, bprocessing bthe binput band boutputs
bthe bdata b
- bControls bthe brest bof bthe bcomputer bsystem b
- bAll bprograms band bdata bare brun bin bthe bCPU
What bis bthe bVon bNewman bArchitecture? b- bcorrect banswer✔✔It bis bthe bdescription
bof bthe bbasic bprocessing bstructure band bcomponents ball bCPUs buse. bIt bstores ba
,bprogram bin bmemory bas binstructions band bexecutes bthem bsequentially busing bthe
bALU, bCU band bregisters. bThis bis bknown bas bthe bstored bprogram bconcept
Give bthe bkey bcomponents bof bthe bway ba bCPU bworks b- bcorrect banswer✔✔- bData
band binstructions bare bboth bstored bas bprimary bdigits
- bData band binstructions bare bboth bstored bin bprimary bmemory b(e.g. bRAM) b
- bInstructions bare bfetched bfrom bmemory bone bat ba btime band bin border b(serially)
- bThe bprocessor bdecodes band bexecutes ban binstruction, bbefore bcycling baround bto
bfetch bthe bnext binstructions b
- bThe bcycle bcontinues buntil bno bmore binstructionsWhat bavailable
What bare bthe bmain bcomponents bof bthe bCPU? b- bcorrect banswer✔✔ALU, bCU,
bclock, bcache, bregisters, bbusses
What bare bthe bfactors bthat baffect bCPU bcomponent b- bcorrect banswer✔✔Clock
bspeed, bcache bsize, bnumber bof bcores, bprocesser btype
What bis bthe bControl bunit? b- bcorrect banswer✔✔The bControl bunit bis ba bcomponent bin
bthe bCPU bincluded bin bthe bVon bNewman bArchitecture bthat bdecodes bthe bprogram's
binstructions b(fetched bfrom bmemory) band btransmits bcontrols bsignals bto bto bother
bhardware bcomponents bto bexecute binstructions.
What bare bthe b2 bmain bcomponents bof bthe bCU? b- bcorrect banswer✔✔- bThe bclock b=
bcoordinates bthe bCPU's bactivity
- bThe bdecoder b= bdecodes bthe bprogram's binstructions
What bis ba bregister band btheir bfunction? b- bcorrect banswer✔✔Registers bare bsmall
bamounts bof bhigh bspeed bmemory bcontained bwithin bthe bCPU. bThey bare bused bbuy
bthe bprocesser bto bstore bsmall bamounts bof bdata bthat bare bneeded bduring
bprocessing, be.g. bthe baddress bof bthe bnext binstruction bto bbe bexecuted, bthe bcurrent
binstruction bbeing bdecoded, band bthe bresult bof bcalculations
What bare bthe b5 bregisters? b- bcorrect banswer✔✔- bProgram bCounter b(PC)
- bMemory bAddress bRegister b(MAR)
- bMemory bData bRegister b(MDR)
- bAccumulator b(ACC)
The bALU bis ba bcomponent bin bthe bCPU. bIt bperforms barithmetic band blogic
bcalculations b- bcorrect banswer✔✔The bALU bis ba bcomponent bin bthe bCPU. bIt
bperforms barithmetic band blogic bcalculations b(decisions), bThe bALU bis bwhere
bcalculations bare bdone band bwhere bdecisions bare bmade. bIt balso bacts bas ba bgateway
bbetween bprimary bmemory band bsecondary bstorage. bData btransferred bbetween bthem
bpasses bthrough bthe bALU.
, What bare bthe bfunctions bof bthe bregisters bin bVon bNewman bArchitecture? b- bcorrect
banswer✔✔- bProgram bCounter b(PC) b= bhols bthe bmemory baddress bof bthe bnext
binstruction bbeing bfetched bfrom bmemory b
- bMemory baddress b(MAR) b= bHolds bthe baddress bof bthe bcurrent binstruction bto bbe
bfetched bfrom bmemory, bor bthe baddress bin bmemory bdata bis bto bbe btransferred btop
- bMemory bData bregister b(MDR) b= bHols bthe bdata bcontents bfound bat baddress bin bthe
bMAR, bor bdata bto bbe btransferred bto bprimary bmemory b
- bAccumulator b(ACC) b= bHolds bthe bresults bof bcalculations
What bis ba bbus band bits bfunction? b- bcorrect banswer✔✔A bbus bis ba bhigh-speed
binternal bconnection, bBusses bare bused bto bsend bcontrol bsignals band bdata bbetween
bthe bprocesser band bother bcomponents.
What bare bthe b3 btypes bof bbusses? b- bcorrect banswer✔✔- bAddress bbus b= bCarries
bmemory baddresses bfrom bthe bprocesser bto bother bcomponents bsuch bas bprimary
bmemory band binput/output bdevices b
- bData bbus b= bCarries bthe bactual bdata bbetween bthe bprocesser band bother
bcomponents b
- bControl bbus b= bCarries bcontrol bsignals bfrom bthe bprocesser bto bother bcomponents.
bThe bcontrol bbus balso bcarries bthe bclock's bpulses
Give ba bdiagram bof bthe bVon bNewman bArchitecture b- bcorrect banswer✔✔
Explain bwhat bhappens bin bthe bfetch-decode-execute bcycle bin bthe b3 bstages b-
bcorrect banswer✔✔1- bFETCH: bThe binstruction bstored bat bthe bmemory baddress bin
bthe bPC bis bfetched. bThe bmemory baddress bis bcopied binto bthe bMAR band bthe
bmemory bcontents bat bthat baddress bin bmemory bare bfetched binto bthe bMDR. bThe bPC
bis bnow bincremented, bshowing bthe bnext binstruction bto bbe bfetched b
2- bDECODE: bThe binstruction bis bcopied bfrom bthe bMDR binto bthe bCU. bThe bCU
bdecodes bthe binstruction band bturn bit binto ba bseries bof bsignals. bIF bmore bdata bis
brequired bthen bthe bCU bsends bout bsignals bto brelevant bcomponents bto bexecute bthe
binstruction be.g. bdo ba bcalculation bin bthe bALU bor boutput binformation. b
3- bEXECUTE: bThe bCU bsends bout bsignals bto brelevant bcomponents bto bexecute bthe
binstruction be.g. bdo ba bcalculation bin bthe bALU bor boutput binformation
- bThe bcycle breturns bto bstep b1 bwith bthe bnext binstruction, brepeating buntil bno bmore
binstructions bare bleft. bA bprogram bis ba bset bof binstructions bstored bin bmain bmemory
b(RAM) bthat ba bCPU bexecutes bsequentially
What bis bthe bdifference bbetween bmain bmemory band bsecondary bstorage b- bcorrect
banswer✔✔Primary bstorage bholds bprograms bcurrently bin buse be.g. bRAM, bcache,
bregisters, bROM. bIt bis balways bvolatile b(except bROM) b- bthe bdata bcontents bare blost
bwhen bpowered boff. bIt bhas ba brelatively bsmaller bstorage bcapacity band bthe bpoint bof
bhaving bit bis bthat bit bis bmuch bquicker bfor bthe bCPU bto baccess bdata bfrom bthe
bprimary bstorage bas bit bis bon bthe bmotherboard. bSecondary bstorage b- bthe boperating
bsystem, blong bterm bprograms band bdata. bIt bis bexternal bto ba bcomputer, bnon bvolatile,
band bhas ba bmuch blarger bstorage bcapacity, be.g. bhard bdisk, bflash bmemory
PAPER 1 QUESTIONS AND CORRECT
ANSWER
Name bsome bof bthe bjobs bgeneral bpurpose bcomputers bcan bdo b- bcorrect banswer✔✔-
bAccess bthe binternet b
- bUse bword bprocessing b
- bPlay bgames b
- bCommunicate bvia bemail/social bmedia b
- bStore band bretrieve bdata b
- bPlay bmusic
What bis ba bgeneral bpurpose bcomputer? b- bcorrect banswer✔✔A bcomputer bdesigned
bto bcarry bout ba bwide brange bof btasks, bfor bexample, ba btablet, bPC, blaptop bor bsmart
bwatch.
What bis ban bembedded bsystem? b- bcorrect banswer✔✔A bsmall bcomputer bthat bforms
bpart bof ba blarger bsystem, bdevice bor bmachine. bIts bpurpose bis bto bcontrol bthe bdevice
band ballow ba buser bto binteract bwith bit, bhave ba bprocessor band bhave binputs band
boutputs. bThey bhave ba blimited bnumber bof btasks bthat bare bspecific bto bits bfunction,
band bare bnot busually bprogrammable bby ba buser
Give bexamples bof bembedded bsystems b- bcorrect banswer✔✔Fitness btrackers, bsmart
bfridges, bcentral bheating bsystems
Advantages bof bembedded bsystems? b- bcorrect banswer✔✔- bTheir blimited bfunctions
bmean bthey bare bcheaper bto bdesign band bbuild
- bThey btend bto brequire bless bpower b(some bdevices brun bfrom bbatteries b
- bThey bdo bnot bneed bmuch bprocessing bpower, bso bthey bcan bbe bbuild bfrom
bcheaper, bpowerful bprocessers b
- bThe bsoftware bin ban bembedded bsystem bcan bbe bupgraded
What bare bcome bcharacteristics bof bembedded bsystems? b- bcorrect banswer✔✔- bLow
bpower bconsumption
- bSmall bsize
- bLow bcost bper bunit
- bRugged boperating branges
,- bNot busually bprogrammable bby bthe buser, bas bthe bprogramming bhas balready bbeen
bdone bby bthe bmanufacturer, bstored bin bROM bchips
In bwhat bways bis ba bwashing bmachine ban bembedded bsystem? b- bcorrect
banswer✔✔It bhas bembedded bsystems bbecause bit bhas ba bCPU bthat bcan bfunction
blike ba bcomputer, bbut bthese bcomputers bare bspecialised bto bdo btheir bspecific btask.
bEmbedded bsystems bare bspecial bcomputers binside ba blarger bdevice. bIts bpurpose bis
bto bcontrol bthe bdevice b(the bwashing bmachine) bas ballows bit bto binteract band breceive
binputs bfrom bits buser. bEmbedded bsystems bare balways ba bcomputer bin ba blarger
bdevice. bThe binput binto ban bembedded bsystem bof ba bwashing bmachine bcan bbe btype
bof bwashing bcycle bthe buser bchooses, bbuttons band bdials bto badjust btemperature band
bthe boutput bcan bbe bwhen bthe bwashing bfinishes, bsounds band blights. bIt bis bsaved bto
bROM bchips bin bthe bcomputer.
What bbasic bmodels bdo ball bgeneral bpurpose bcomputers bfollow? b- bcorrect
banswer✔✔The bgeneral bpurpose bmodel:
- bData bis binput, band bthen beither boutput bor bsent bto bsecondary bstorage bafter bbeing
bprocessed. bIt bis bheld bis bprimary bmemory bwhile bbeing bprocessed
What bare binput bdevices? b- bcorrect banswer✔✔- bA bdevice bused bto benter bdata bor
binformation binto ba bcomputer b(e.g. ba bmouse, bkeyboard, bscanner bor bmicrophone)
What bare boutput bdevices? b- bcorrect banswer✔✔- bA bdevice bused bto breturn
binformation bfrom ba bcomputer, be.g. ba bmonitor, bprinter bor bspeaker
What bhappens bwith binputs band boutputs bin ba bcomputer? b- bcorrect banswer✔✔The
bCPU breceives bdata band binstructions bfrom ban binput bor bmemory. bThe bins
What bis bhardware band bsoftware? b- bcorrect banswer✔✔Hardware b= bphysical
bcomponents bof bthe bcomputer be.g. bCPU, bhard bdisk, bmonitor b
Software= bPrograms bthat brun bon ba bcomputer
What bare bperipherals? b- bcorrect banswer✔✔Pieces bof bhardware bthat bconnect bto ba
bcomputer band bare badded bto ba bcomputer bto bexpand bits babilities be.g. bmouse,
bkeyboard, bprinter, bscanner. bThey bare binput/output bdevices
What bis bthe bpurpose bof bthe bCPU b- bcorrect banswer✔✔(Central bprocessing bunit)
- bTo bprocess bdata band binstructions bby bcarrying bout bthe bfetch, bdecode bexecute
bcycle b
- bThe bbrain bof bthe bcomputer b- btakes ban binput, bprocessing bthe binput band boutputs
bthe bdata b
- bControls bthe brest bof bthe bcomputer bsystem b
- bAll bprograms band bdata bare brun bin bthe bCPU
What bis bthe bVon bNewman bArchitecture? b- bcorrect banswer✔✔It bis bthe bdescription
bof bthe bbasic bprocessing bstructure band bcomponents ball bCPUs buse. bIt bstores ba
,bprogram bin bmemory bas binstructions band bexecutes bthem bsequentially busing bthe
bALU, bCU band bregisters. bThis bis bknown bas bthe bstored bprogram bconcept
Give bthe bkey bcomponents bof bthe bway ba bCPU bworks b- bcorrect banswer✔✔- bData
band binstructions bare bboth bstored bas bprimary bdigits
- bData band binstructions bare bboth bstored bin bprimary bmemory b(e.g. bRAM) b
- bInstructions bare bfetched bfrom bmemory bone bat ba btime band bin border b(serially)
- bThe bprocessor bdecodes band bexecutes ban binstruction, bbefore bcycling baround bto
bfetch bthe bnext binstructions b
- bThe bcycle bcontinues buntil bno bmore binstructionsWhat bavailable
What bare bthe bmain bcomponents bof bthe bCPU? b- bcorrect banswer✔✔ALU, bCU,
bclock, bcache, bregisters, bbusses
What bare bthe bfactors bthat baffect bCPU bcomponent b- bcorrect banswer✔✔Clock
bspeed, bcache bsize, bnumber bof bcores, bprocesser btype
What bis bthe bControl bunit? b- bcorrect banswer✔✔The bControl bunit bis ba bcomponent bin
bthe bCPU bincluded bin bthe bVon bNewman bArchitecture bthat bdecodes bthe bprogram's
binstructions b(fetched bfrom bmemory) band btransmits bcontrols bsignals bto bto bother
bhardware bcomponents bto bexecute binstructions.
What bare bthe b2 bmain bcomponents bof bthe bCU? b- bcorrect banswer✔✔- bThe bclock b=
bcoordinates bthe bCPU's bactivity
- bThe bdecoder b= bdecodes bthe bprogram's binstructions
What bis ba bregister band btheir bfunction? b- bcorrect banswer✔✔Registers bare bsmall
bamounts bof bhigh bspeed bmemory bcontained bwithin bthe bCPU. bThey bare bused bbuy
bthe bprocesser bto bstore bsmall bamounts bof bdata bthat bare bneeded bduring
bprocessing, be.g. bthe baddress bof bthe bnext binstruction bto bbe bexecuted, bthe bcurrent
binstruction bbeing bdecoded, band bthe bresult bof bcalculations
What bare bthe b5 bregisters? b- bcorrect banswer✔✔- bProgram bCounter b(PC)
- bMemory bAddress bRegister b(MAR)
- bMemory bData bRegister b(MDR)
- bAccumulator b(ACC)
The bALU bis ba bcomponent bin bthe bCPU. bIt bperforms barithmetic band blogic
bcalculations b- bcorrect banswer✔✔The bALU bis ba bcomponent bin bthe bCPU. bIt
bperforms barithmetic band blogic bcalculations b(decisions), bThe bALU bis bwhere
bcalculations bare bdone band bwhere bdecisions bare bmade. bIt balso bacts bas ba bgateway
bbetween bprimary bmemory band bsecondary bstorage. bData btransferred bbetween bthem
bpasses bthrough bthe bALU.
, What bare bthe bfunctions bof bthe bregisters bin bVon bNewman bArchitecture? b- bcorrect
banswer✔✔- bProgram bCounter b(PC) b= bhols bthe bmemory baddress bof bthe bnext
binstruction bbeing bfetched bfrom bmemory b
- bMemory baddress b(MAR) b= bHolds bthe baddress bof bthe bcurrent binstruction bto bbe
bfetched bfrom bmemory, bor bthe baddress bin bmemory bdata bis bto bbe btransferred btop
- bMemory bData bregister b(MDR) b= bHols bthe bdata bcontents bfound bat baddress bin bthe
bMAR, bor bdata bto bbe btransferred bto bprimary bmemory b
- bAccumulator b(ACC) b= bHolds bthe bresults bof bcalculations
What bis ba bbus band bits bfunction? b- bcorrect banswer✔✔A bbus bis ba bhigh-speed
binternal bconnection, bBusses bare bused bto bsend bcontrol bsignals band bdata bbetween
bthe bprocesser band bother bcomponents.
What bare bthe b3 btypes bof bbusses? b- bcorrect banswer✔✔- bAddress bbus b= bCarries
bmemory baddresses bfrom bthe bprocesser bto bother bcomponents bsuch bas bprimary
bmemory band binput/output bdevices b
- bData bbus b= bCarries bthe bactual bdata bbetween bthe bprocesser band bother
bcomponents b
- bControl bbus b= bCarries bcontrol bsignals bfrom bthe bprocesser bto bother bcomponents.
bThe bcontrol bbus balso bcarries bthe bclock's bpulses
Give ba bdiagram bof bthe bVon bNewman bArchitecture b- bcorrect banswer✔✔
Explain bwhat bhappens bin bthe bfetch-decode-execute bcycle bin bthe b3 bstages b-
bcorrect banswer✔✔1- bFETCH: bThe binstruction bstored bat bthe bmemory baddress bin
bthe bPC bis bfetched. bThe bmemory baddress bis bcopied binto bthe bMAR band bthe
bmemory bcontents bat bthat baddress bin bmemory bare bfetched binto bthe bMDR. bThe bPC
bis bnow bincremented, bshowing bthe bnext binstruction bto bbe bfetched b
2- bDECODE: bThe binstruction bis bcopied bfrom bthe bMDR binto bthe bCU. bThe bCU
bdecodes bthe binstruction band bturn bit binto ba bseries bof bsignals. bIF bmore bdata bis
brequired bthen bthe bCU bsends bout bsignals bto brelevant bcomponents bto bexecute bthe
binstruction be.g. bdo ba bcalculation bin bthe bALU bor boutput binformation. b
3- bEXECUTE: bThe bCU bsends bout bsignals bto brelevant bcomponents bto bexecute bthe
binstruction be.g. bdo ba bcalculation bin bthe bALU bor boutput binformation
- bThe bcycle breturns bto bstep b1 bwith bthe bnext binstruction, brepeating buntil bno bmore
binstructions bare bleft. bA bprogram bis ba bset bof binstructions bstored bin bmain bmemory
b(RAM) bthat ba bCPU bexecutes bsequentially
What bis bthe bdifference bbetween bmain bmemory band bsecondary bstorage b- bcorrect
banswer✔✔Primary bstorage bholds bprograms bcurrently bin buse be.g. bRAM, bcache,
bregisters, bROM. bIt bis balways bvolatile b(except bROM) b- bthe bdata bcontents bare blost
bwhen bpowered boff. bIt bhas ba brelatively bsmaller bstorage bcapacity band bthe bpoint bof
bhaving bit bis bthat bit bis bmuch bquicker bfor bthe bCPU bto baccess bdata bfrom bthe
bprimary bstorage bas bit bis bon bthe bmotherboard. bSecondary bstorage b- bthe boperating
bsystem, blong bterm bprograms band bdata. bIt bis bexternal bto ba bcomputer, bnon bvolatile,
band bhas ba bmuch blarger bstorage bcapacity, be.g. bhard bdisk, bflash bmemory
