๐ Std 4 โ Computer
๐พ Chapter 1: Memory and Storage
๐น Computer Memory
Computer memory is the storage area where data and instructions are stored. It includes short-term and long-term storage.
๐น Data Storage Units
- Bit (0 or 1)
- 1 Byte = 8 bits
- 1 KB = 1024 Bytes
- 1 MB = 1024 KB
- 1 GB = 1024 MB
- 1 TB = 1024 GB
๐น Types of Memory
- Primary Memory: RAM, ROM
- Secondary Memory: Hard Disk, Pen Drive, CD, DVD, etc.
๐น RAM
RAM stores data temporarily. Data is lost when computer is turned off. It is called volatile memory.
๐น ROM
ROM stores permanent instructions. Data is not lost when power is off. It is non-volatile memory.
๐น Secondary Storage Devices
- Hard Disk
- SSD
- CD / DVD / Blu-ray
- Pen Drive
- Memory Card
- Cloud Storage
๐น RAM vs ROM
| RAM | ROM |
|---|---|
| Temporary | Permanent |
| Data lost | Data safe |
| Volatile | Non-volatile |
โ๏ธ A. Fill in the blanks
- Data is measured in Bytes.
- RAM and ROM are types of internal memory.
- Pen drive is also called Flash Drive.
- A CD can store up to 700 MB and is 4.7 inches.
โ๏ธ B. True or False
- RAM stands for Random Access Memory โ True
- SSD gives high performance โ True
- Flash drive is small and rewritable โ True
- 1 MB = 1024 GB โ False
๐ C. Multiple Choice Questions
- 0 and 1 are called Binary
- Temporary memory is RAM
- Blu-ray uses Blue-violet Laser
- Data lost when off โ RAM
๐ D. Match the Following
- ROM โ Internal Memory
- DVD โ 4.7 GB
- Blu-ray Disc โ 50 GB
- Flash Drive โ Plug-and-Play Device
๐ง E. Competency Questions
- Use Pen Drive
- Use External Hard Disk
๐ F. Answer the Following
- Primary Memory: Built-in memory (RAM & ROM).
- Hard Disk: Stores large data permanently.
- Cloud Storage Benefits: Access anywhere, backup safe.
- Memory Card: Used in mobiles for storage.
- RAM vs ROM: RAM temporary, ROM permanent.
