Std 4 Computer – Memory and Storage

📘 Std 4 – Computer

💾 Chapter 1: Memory and Storage

🔹 Computer Memory

Computer memory is the storage area where data and instructions are stored. It includes short-term and long-term storage.

🔹 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

🔹 Types of Memory

  • Primary Memory: RAM, ROM
  • Secondary Memory: Hard Disk, Pen Drive, CD, DVD, etc.

🔹 RAM

RAM stores data temporarily. Data is lost when computer is turned off. It is called volatile memory.

🔹 ROM

ROM stores permanent instructions. Data is not lost when power is off. It is non-volatile memory.

🔹 Secondary Storage Devices

  • Hard Disk
  • SSD
  • CD / DVD / Blu-ray
  • Pen Drive
  • Memory Card
  • Cloud Storage

🔹 RAM vs ROM

RAMROM
TemporaryPermanent
Data lostData safe
VolatileNon-volatile

✏️ A. Fill in the blanks

  1. Data is measured in Bytes.
  2. RAM and ROM are types of internal memory.
  3. Pen drive is also called Flash Drive.
  4. A CD can store up to 700 MB and is 4.7 inches.

✔️ B. True or False

  1. RAM stands for Random Access Memory – True
  2. SSD gives high performance – True
  3. Flash drive is small and rewritable – True
  4. 1 MB = 1024 GB – False

🔘 C. Multiple Choice Questions

  1. 0 and 1 are called Binary
  2. Temporary memory is RAM
  3. Blu-ray uses Blue-violet Laser
  4. Data lost when off → RAM

🔗 D. Match the Following

  • ROM → Internal Memory
  • DVD → 4.7 GB
  • Blu-ray Disc → 50 GB
  • Flash Drive → Plug-and-Play Device

🧠 E. Competency Questions

  1. Use Pen Drive
  2. Use External Hard Disk

📝 F. Answer the Following

  1. Primary Memory: Built-in memory (RAM & ROM).
  2. Hard Disk: Stores large data permanently.
  3. Cloud Storage Benefits: Access anywhere, backup safe.
  4. Memory Card: Used in mobiles for storage.
  5. RAM vs ROM: RAM temporary, ROM permanent.