USB – Universal Serial Bus
🔹 Definition:
USB (Universal Serial Bus) is a plug-and-play interface used to connect peripherals (external devices) to a computer and transfer data or provide power.
🔹 Full Form:
USB – Universal Serial Bus
🔹 Key Features:
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Used for data transfer and device charging.
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Plug-and-play: No need to restart the computer.
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Hot-swappable (can be connected/removed without shutting down).
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Supports multiple devices (keyboard, mouse, pendrive, printer, etc.).
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Replaces older ports like serial and parallel ports.
🔹 Common USB Devices:
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Pen drives
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External hard drives
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Mobile phones
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Keyboards & mice
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Printers & scanners
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Webcams
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Game controllers
🔹 Types of USB Ports:
| USB Version | Speed | Data Rate |
|---|---|---|
| USB 1.1 | Low/Full Speed | 12 Mbps |
| USB 2.0 | High Speed | 480 Mbps |
| USB 3.0 | Super Speed | 5 Gbps |
| USB 3.1 | SuperSpeed+ | 10 Gbps |
| USB 3.2 | Enhanced Speed | 20 Gbps |
| USB4 | Latest Version | 40 Gbps |
🔹 Types of USB Connectors:
| Connector Type | Description |
|---|---|
| USB-A | Standard flat connector (PC, laptop) |
| USB-B | Used in printers |
| USB-C | Newest, reversible, faster |
| Mini/Micro USB | Older mobile devices |
🔹 Advantages:
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Universal compatibility
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Portable and easy to use
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Supports fast data transfer
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Provides power supply to devices
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Supports up to 127 devices through daisy-chaining
📝 Important Points for Exam:
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USB allows data transfer and power supply through a single cable.
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USB 3.0 port is usually blue in color.
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USB-C is reversible and supports fast charging and high data speed.
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USB replaced old ports like serial, parallel, PS/2.
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Maximum number of devices supported by USB: 127
❓ Previous Year MCQs (PYQs)
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The full form of USB is:
a) Universal Signal Bus
b) United Serial Bus
c) Universal Serial Bus ✅
d) Unified Service Bus -
Which of the following is a USB port used for?
a) Connecting monitors
b) Transferring data ✅
c) Increasing RAM
d) None of these -
What is the maximum number of devices that can be connected via USB?
a) 32
b) 64
c) 127 ✅
d) 255 -
Which USB version provides the fastest speed?
a) USB 2.0
b) USB 3.0
c) USB4 ✅
d) USB 1.1 -
Which of the following USB types is reversible?
a) USB-A
b) USB-B
c) USB-C ✅
d) Micro USB
📌 Summary for Quick Revision:
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USB = Universal Serial Bus
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Used for: Data transfer + Power supply
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Latest version: USB4 (40 Gbps)
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Latest connector: USB-C
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Can connect up to 127 devices
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Found in: Pen drives, phones, printers, external HDD, mouse, keyboard, etc.
USB MCQs for Competitive Exams
🔹 MCQ Set:
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What does USB stand for?
a) United Serial Bus
b) Universal Serial Bus ✅
c) Universal Signal Bus
d) Uniform Storage Bus
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Which of the following devices commonly uses a USB port?
a) Monitor
b) Keyboard ✅
c) Processor
d) RAM
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USB is used for:
a) Only charging devices
b) Only connecting devices
c) Transferring data and power ✅
d) Only storing data
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Which USB version offers the highest data transfer speed?
a) USB 2.0
b) USB 3.0
c) USB 3.1
d) USB4 ✅
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What is the maximum number of devices that can be connected to a single USB port using hubs?
a) 64
b) 127 ✅
c) 255
d) 512
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Which of the following USB types is reversible?
a) USB-A
b) USB-B
c) USB-C ✅
d) Micro-USB
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USB ports replaced which of the following older ports?
a) Serial and Parallel ports ✅
b) HDMI ports
c) Audio jacks
d) RAM slots
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USB devices are known to be:
a) Non-pluggable
b) Hot-swappable ✅
c) Non-removable
d) BIOS dependent
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Which color is commonly used for USB 3.0 ports?
a) Black
b) White
c) Blue ✅
d) Red
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What type of storage is a USB pen drive?
a) Optical
b) Magnetic
c) Flash ✅
d) ROM
🟩 Score Yourself:
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9–10 Correct: ✅ Excellent – USB master!
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7–8 Correct: 👍 Good – Almost exam-ready
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5–6 Correct: 🔄 Revise key points again
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Below 5: 📚 Go through the notes above again