Magnetic Disk - Notes for Exam
✅ Definition
A magnetic disk is a type of non-volatile storage device that uses magnetization to store data. Data is stored in concentric tracks and sectors on the disk's surface.
🔁 How It Works
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Data is written and read using a read/write head.
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The disk rotates, and the head moves to access different tracks.
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Data is stored in binary form (0s and 1s) using magnetic polarity.
📌 Examples of Magnetic Disks
| Type | Description | Capacity |
|---|---|---|
| Hard Disk Drive (HDD) | Common magnetic storage device in computers | GBs to TBs |
| Floppy Disk | Old portable storage, now obsolete | 1.44 MB |
| Zip Disk | Used in 1990s, more capacity than floppy | Up to 750 MB |
📍 Important Features
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Rewritable multiple times.
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Random access: Any part of data can be accessed directly.
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High storage capacity, especially HDDs.
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Data remains even when power is off.
💡 Advantages
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High capacity (now up to 20 TB in HDDs).
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Cheaper per GB than SSDs.
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Reliable for storing large files.
⚠️ Disadvantages
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Slower than SSDs.
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Sensitive to physical damage and magnets.
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Mechanical parts can wear out.
📘 MCQs on Magnetic Disk (with answers)
Q1. Which of the following is a magnetic storage device?
A) CD
B) Pen Drive
C) HDD
D) Blu-ray Disc
✅ Answer: C
Q2. Data in magnetic disks is stored using:
A) Electric charge
B) Laser light
C) Magnetic field
D) Optical sensors
✅ Answer: C
Q3. Which device uses magnetic disk technology?
A) SSD
B) HDD
C) DVD
D) ROM
✅ Answer: B
Q4. What is the storage capacity of a standard floppy disk?
A) 700 MB
B) 1.44 MB
C) 4.7 GB
D) 500 GB
✅ Answer: B
Q5. Which is faster in accessing data?
A) Magnetic tape
B) Magnetic disk
C) Optical disk
D) Punch card
✅ Answer: B
Q6. Which component reads data from a magnetic disk?
A) Laser beam
B) Magnetic strip
C) Read/Write Head
D) Power supply
✅ Answer: C
Q7. What is one main disadvantage of magnetic disks?
A) High cost
B) Very small size
C) Slower than SSDs and vulnerable to damage
D) Cannot rewrite data
✅ Answer: C
Q8. Which one is now obsolete?
A) Hard Disk
B) SSD
C) Floppy Disk
D) Magnetic Tape
✅ Answer: C