Edexcel GCSE Computer Science (1CP2) Exam Questions

• B To reduce the time taken to transmit a file (1)
• The only correct answer is B. The correct answer is to reduce the time taken to transmit a file.
• A is not correct because compression reduces file size, which can reduce the number of packets sent
• C is not correct because lossy compression can reduce the quality of a file
• D is not correct because encryption, not compression, can make a file harder to open

• B The destination IP address (1)
• The only correct answer is B. The correct answer is the destination IP address.
• A is not correct because a domain name is converted to an IP address by a DNS server before routing begins
• C is not correct because the sender's MAC address is only used to deliver the packet on the local network
• D is not correct because the file name is not used to route packets

Award one mark for each of:

• 5 × 1024^3 / 5 × 1024 × 1024 × 1024 / 5 × 2^30, for the number of bytes (1)
• A fully correct expression with × 8 to convert bytes to bits, in any order, e.g. 5 × 1024^3 × 8, 8 × 5 × 2^30 (1)

Accept 5 × 1 073 741 824 × 8.

Accept 5 × 2^33 or 42 949 672 960 as a fully correct expression (2 marks).

Do not accept 5 × 1000^3 × 8, which uses decimal multiples.

Do not accept ÷ 8, which converts bits to bytes.

Award up to two marks for a linked description such as:

• The user enters a username/user ID and password/PIN (1) which is compared with the account details the operating system has stored (1)
• The operating system keeps a file/list/database of users and their passwords (1) to check the login details the user enters against (1)
• The operating system compares the entered details with the details stored for that user (1) and if they do not match, access is refused/denied (1)
• The entered details are checked against the access rights stored for that user (1) so access is only allowed when the details are correct (1)

Do not award for 'it asks for a password' on its own, without saying what the password is checked against.

A stored list/file of users and passwords with no check of the login details earns one mark only.

Do not accept responses about file management, such as finding or opening the user's files.

Award up to two marks for a linked description such as:

• The processor/CPU can only execute machine code/binary instructions (1) so the assembly instructions must be converted into machine code before the program can run (1)
• Each assembly instruction/mnemonic matches/corresponds to one machine code instruction (1) so each line must be replaced with the machine code the processor executes (1)
• The program is written using mnemonics (1) that must be translated into machine code for the processor to carry out the instructions (1)
• The hardware/processor does not understand assembly language directly (1) so it must be translated into machine code that the processor can execute (1)

Do not accept 'assembly language is a low-level language'.

Do not accept 'it is hard to understand' or 'it is not English'.

Do not accept benefits, such as 'machine code runs faster' or 'the program will run more quickly'.

Do not accept 'an assembler/a translator converts it' on its own, with no reference to the processor only being able to execute machine code/binary.

Do not accept responses about high-level languages or about compilers/interpreters.

Award one mark for each correct nibble in the correct order:

• 1100 (1)
• 0111 (1)

0 marks if the response is not 8-bit binary.