exam questions Flashcards
Tracking cookies can be created and used when browsing a website.
Describe a security risk associated with tracking cookies.
Unauthorised access to personal
data (sent to third parties
through the tracking cookie)
Explain how public and private keys help to keep these details secure when
transmitted between the customer and the bank’s server
A public key is used to encrypt
the personal data (1)
A private key is used to
decrypt the personal data
Describe how watchpoints are used to help programmers locate errors
Watchpoints are used to stop
execution when the value of a
specific variable changes/predetermined conditions are met. (1)
This allows the programmer to
compare the value with the
expected value (1)
Describe two benefits of using local variables.
More efficient as memory
assigned to a local variable
becomes available once
function is terminated (1)
Aids modularity (1)
Describe the process of usability testing of the new website.
Users given task/scenario to
perform on the software (1)
Feedback is given to
developers (1)
Move some cat ears ? State
whether this task is easier to do with the bitmapped or the vector
graphic. Explain your answer
Vector (1 mark)
Ear could be grouped as a set
of objects
Describe the effect on the file size of adding the star to both the
vector and bitmapped graphic.
Vector increases
Bitmap stays the same
Describe the steps of
the fetch-execute cycle.
Address of instruction placed on address bus Read line (on control bus) is activated Contents of location (instruction) transferred to a register along data bus Instruction decoded/executed
Explain how cache improves performance
Stores frequently accessed
instructions/data
Faster access times than main
memory
Describe the difference between a bit depth of 16 bits and that of 24 bits
for the quality of video.
24 bit can store more than 16 million colours
16 can store 6.5K colours
more colours
Pupils access files from a shared folder on their school network server.
These
files are available for the pupils to open, but only a teacher can edit and save
the files to this folder.
Describe how this is implemented.
Pupils have read only access to
this folder (1)
Teachers have read/write
access to this folder (1)
Explain why a compound key is could be required for table
No single field provides a unique
value
State two
items that would be specified in a data dictionary.
Field/data type Keys / PK/FK Validation Field length/size Format Required Unique Sample data Table name
State one reason why the increased use of technology has had a negative
effect on the environment.
Answer must refer to
manufacture, use or disposal of
technology.
State two benefits of using parameter passing rather than global
variables.
code is more readable/easier to
maintain
Aids modularity
Reduces impact or load on
main memory
Explain
what is meant by a function.
Returns a single value
Emma’s home computer has a data bus and an address bus.
Describe how each bus is used when reading data from memory.
The address bus stores/carries/holds the address of the memory location of the data (currently being accessed/read from) The data bus transfers data to the processor/register
Other than a trace table, name and describe a technique that Tony could
use to locate and identify the error.
Dry Run or Breakpoint
Manual run through of code often
involving a pen and paper to try to
identify errors
breakpoint- Stop the program
Explain the difference between a public key and a private key when securing
the transmission of data.
A public key is used to encrypt the
personal data. (1 mark)
A private key is used to decrypt the
personal data.
Describe an advantage of using Unicode over ASCII, making reference to the
number of bits used to represent a character in each format.
Unicode can represent more
characters.
uses 16 bits compared to 8/7.
State other trend that improves performance.
part (a)
Describe how your answer to part (a) improves performance.
Multi-core/number of processors. Increase width of data bus. Increase clock speed. Increase RAM/memory. Increase use of solid state. Any other valid response.
Matching reason eg Simultaneous execution of instructions/parallel processing. More bits transferred in a single operation. More fetch-executes per clock pulse. Reduces the need/faster access to access slower backing storage. Faster access than slower backing storage.
Using pseudocode or a programming language of your choice,
declare the variable which can store the details of the top 100
movies.
DECLARE topMovies AS ARRAY
OF movie INITIALLY[]*99
State the scope of the min variable. Explain your answer.
Local
It is only used within the function
in which it is declared.
Explain the role of the memory management function of the operating
system when a user loads the SportsStats program
Tracks/checks available memory.
Allocates space/addresses in RAM
for the function.
Protects other processes.
John has downloaded a new computer game but finds that it does not run on
his computer
a) State one software reason why the game may not be compatible
(b) State one hardware reason why the game may not be compatible.
part A
Version of/out of date operating system.
Downloaded file is corrupt
Part B Insufficient amount of RAM/memory. Minimum clock speed not available. Version of processor. Version of graphics card
SecureBell stores customer videos on a public cloud.
(i) State two reasons why SecureBell chooses to use a public cloud
rather than a private cloud to store the videos.
Public cloud services can be easily increased or decreased to match current needs.
Can set up or easily expand capacity of public cloud storage without (Securebell) purchasing hardware.
Public cloud removes need for backup/maintenance/ administration strategies (for SecureBell).
Public cloud has lower initial costs than private cloud.
Say the Update
Delete
Insert
Querys
Update
Set
Where
Insert Into
values
Delete From
Where
Explain why tracking cookies are also known as third-party cookies.
Tracking cookies do not originate from the website
operator/owner but from a third party – such as an
advertiser or social network. (1 mark) 1
Describe the following type of DOS attack:
Domain Name Service
A large volume of DNS queries to different DNS servers are made at the same time using a spoofed address of the target service. The DNS servers return responses overloading the attacked system and a denial of service to legitimate users.
A real number is stored using 32-bit floating point representation. The
mantissa is allocated 24 bits and 8 bits are allocated to the exponent.
Describe the effect if the allocation is changed to a 16-bit mantissa and a
16-bit exponent.
Precision will decrease (1)
Range will increase
Explain how multi-core processors are used as a technique to
increase processor performance
Each core is a separate processing unit within the processor (1 mark). Adding additional cores allows the processor to run execute multiple instructions at the same time (1 mark)
