J276 OCR Computer Science Unit 2.6 Revision Sheets / Practice Questions

Here you will find easy to follow revision sheets which will help your students to recap the topic:

2.6 Data Representation

Units

• bit, nibble, byte, kilobyte, megabyte, gigabyte, terabyte, petabyte
• how data needs to be converted into a binary format to be processed by a computer.
  Numbers
• how to convert positive denary whole numbers (0–255) into 8 bit binary numbers and vice versa
• how to add two 8 bit binary integers and explain overflow errors which may occur
• binary shifts
• how to convert positive denary whole numbers (0–255) into 2 digit hexadecimal numbers and vice
• versa
• how to convert from binary to hexadecimal equivalents and vice versa
• check digits.
  Characters
• the use of binary codes to represent characters
• the term ‘character-set’
• the relationship between the number of bits per character in a character set and the number of
• characters which can be represented (for example ASCII, extended ASCII and Unicode).
  Images
• how an image is represented as a series of pixels represented in binary
• metadata included in the file
• the effect of colour depth and resolution on the size of an image file.
  Sound
• how sound can be sampled and stored in digital form
• how sampling intervals and other factors affect the size of a sound file and the quality of its playback:
• sample size
• bit rate
• sampling frequency.
  Compression
• need for compression
• types of compression:
• lossy
• lossless.

The revision sheets include exam questions at the end of each topic to help the students recap their revision and apply it to a question.

Check out my shop to save on buying multiple sheets!!

Enjoy!