Units of memory: Class 11 practice
1 byte = 8 bits; 1 KB = 1024 bytes; 1 MB = 1024 KB; 1 GB = 1024 MB; 1 TB = 1024 GB (binary units used in the CBSE syllabus).. Read the method, follow the three worked examples, then try the six questions.
What you should know first
- Powers of 2
The idea behind units of memory
1 byte = 8 bits; 1 KB = 1024 bytes; 1 MB = 1024 KB; 1 GB = 1024 MB; 1 TB = 1024 GB (binary units used in the CBSE syllabus).
Step-by-step method
- Write the conversion chain.
- Multiply to go to smaller units, divide to go to larger.
- Count powers of 1024 (2¹⁰).
Worked example 1 (Basic)
How many bits are in 7 KB?
- 7 KB = 7 × 1024 bytes = 7168 bytes
- × 8 = 57344 bits
- Answer: 57344 bits
Worked example 2 (Standard)
How many MB are in 13312 KB?
- ÷ 1024
- = 13 MB
- Answer: 13 MB
Worked example 3 (Challenge)
How many 5 MB songs fit on a 4 GB card?
- 4 GB = 4096 MB
- 4096 ÷ 5 = 819 (whole songs)
- Answer: 819
Common mistakes and misconceptions
- Using 1000 instead of 1024 when the syllabus uses binary units
- Forgetting 8 bits per byte
Practice questions
- (Basic) How many bits are in 8 KB?
- (Basic) How many bits are in 15 KB?
- (Standard) How many MB are in 1024 KB?
- (Standard) How many MB are in 12288 KB?
- (Challenge) How many 4 MB songs fit on a 8 GB card?
- (Challenge) How many 4 MB songs fit on a 4 GB card?
Answer key with full working
- Q1: 8 KB = 8 × 1024 bytes = 8192 bytes → × 8 = 65536 bits → Answer: 65536 bits
- Q2: 15 KB = 15 × 1024 bytes = 15360 bytes → × 8 = 122880 bits → Answer: 122880 bits
- Q3: ÷ 1024 → = 1 MB → Answer: 1 MB
- Q4: ÷ 1024 → = 12 MB → Answer: 12 MB
- Q5: 8 GB = 8192 MB → 8192 ÷ 4 = 2048 (whole songs) → Answer: 2048
- Q6: 4 GB = 4096 MB → 4096 ÷ 4 = 1024 (whole songs) → Answer: 1024
Syllabus note
This skill is listed under "Computer Systems and Organisation" for Class 11 in the NCERT/CBSE books. ICSE, IGCSE, IB and state boards may teach it in a different chapter or year.
Answers on this page are generated and automatically re-checked by a second, independent calculation. They have not been reviewed by a teacher — if you spot a problem, tell us on WhatsApp.
Related practice and notes
Frequently asked questions
Which chapter is units of memory in?
"Computer Systems and Organisation", Class 11 Computer Science (NCERT/CBSE). Other boards may place it differently.
How were the answers checked?
Answers on this page are generated and automatically re-checked by a second, independent calculation. They have not been reviewed by a teacher — if you spot a problem, tell us on WhatsApp.