1. What is a single-bit error?
A) Error affecting multiple bits
B) Error affecting only one bit
C) Error in transmission medium
D) Error in protocol
Show Explanation
2. What characterizes a burst error?
A) Multiple consecutive bits are affected
B) Only one bit is affected
C) Random bits are affected
D) No bits are affected
Show Explanation
3. Which is the simplest error detection method?
A) CRC
B) Checksum
C) Parity check
D) Hamming code
Show Explanation
4. What does CRC stand for?
A) Cyclic Redundancy Code
B) Cyclic Redundancy Check
C) Circular Redundancy Check
D) Cyclic Reliability Check
Show Explanation
5. Which error correction method can correct single-bit errors?
A) Hamming code
B) Parity check
C) CRC
D) Checksum
Show Explanation
6. What is framing in the data link layer?
A) Error detection process
B) Flow control mechanism
C) Dividing data into frames
D) Address resolution process
Show Explanation
7. In Stop-and-Wait ARQ, what happens after sending a frame?
A) Immediately send next frame
B) Wait for acknowledgment
C) Send multiple frames
D) Discard the frame
Show Explanation
8. What is the main advantage of Go-Back-N ARQ over Stop-and-Wait?
A) Multiple frames can be sent without waiting
B) Better error detection
C) Simpler implementation
D) Lower bandwidth usage
Show Explanation
9. In Selective Repeat ARQ, which frames are retransmitted?
A) All frames from the error point
B) The last transmitted frame
C) Only the frames in error
D) All frames in the window
Show Explanation
10. What is the purpose of flow control?
A) Error detection
B) Control data transmission rate
C) Address resolution
D) Data encryption
Show Explanation
11. Which multiple access protocol is used in Ethernet?
A) CSMA/CD
B) CSMA/CA
C) TDMA
D) FDMA
Show Explanation
12. What type of access method is ALOHA?
A) Controlled access
B) Random access
C) Channelization
D) Deterministic access
Show Explanation
13. Which is an example of controlled access protocol?
A) CSMA/CD
B) ALOHA
C) Token passing
D) Slotted ALOHA
Show Explanation
14. What does FDMA stand for?
A) Frequency Division Multiple Access
B) Frame Division Multiple Access
C) Full Duplex Multiple Access
D) Fast Division Multiple Access
Show Explanation
15. In TDMA, how is the channel shared?
A) By frequency
B) By time slots
C) By code sequences
D) By power levels
Show Explanation
16. What does CDMA use to distinguish between users?
A) Different frequencies
B) Different time slots
C) Different code sequences
D) Different power levels
Show Explanation
17. What does MAC address stand for?
A) Media Access Control
B) Multiple Access Control
C) Message Authentication Code
D) Memory Access Control
Show Explanation
18. How many bits are there in a MAC address?
A) 32 bits
B) 48 bits
C) 64 bits
D) 128 bits
Show Explanation
19. What is the main difference between ALOHA and Slotted ALOHA?
A) Different frequency bands
B) Different power levels
C) Time is divided into slots
D) Different coding schemes
Show Explanation
20. At which layer does a switch operate?
A) Data Link layer
B) Physical layer
C) Network layer
D) Transport layer
Show Explanation
21. What is the main advantage of sliding window protocol?
A) Better error detection
B) Multiple frames in transit
C) Simpler implementation
D) Lower overhead
Show Explanation
22. Which protocol is commonly used in wireless LANs?
A) CSMA/CD
B) Token Ring
C) CSMA/CA
D) FDDI
Show Explanation
23. What is the minimum frame size in Ethernet?
A) 64 bytes
B) 32 bytes
C) 128 bytes
D) 256 bytes
Show Explanation
24. What is the maximum frame size in Ethernet?
A) 1024 bytes
B) 1518 bytes
C) 2048 bytes
D) 4096 bytes
Show Explanation
25. What algorithm is used for collision resolution in CSMA/CD?
A) Round robin
B) First come first served
C) Binary exponential backoff
D) Priority scheduling
Show Explanation
26. Which protocol is used for point-to-point connections?
A) PPP
B) Ethernet
C) Token Ring
D) FDDI
Show Explanation
27. What type of protocol is HDLC?
A) Character-oriented
B) Bit-oriented
C) Byte-oriented
D) Frame-oriented
Show Explanation
28. What does window size represent in sliding window protocol?
A) Frame size
B) Buffer size
C) Number of frames that can be sent
D) Transmission speed
Show Explanation
29. What is bit stuffing used for?
A) Preventing flag sequences in data
B) Error correction
C) Flow control
D) Address resolution
Show Explanation
30. When is character stuffing used?
A) In bit-oriented protocols
B) In character-oriented protocols
C) In error detection
D) In flow control
Show Explanation
31. What is a disadvantage of Stop-and-Wait ARQ?
A) Complex implementation
B) High error rate
C) Low efficiency
D) High bandwidth usage
Show Explanation
32. In Go-Back-N ARQ, what happens when an error is detected?
A) All frames from error point are retransmitted
B) Only the error frame is retransmitted
C) The last frame is retransmitted
D) No retransmission occurs
Show Explanation
33. Which ARQ method is most efficient?
A) Stop-and-Wait
B) Selective Repeat
C) Go-Back-N
D) All are equally efficient
Show Explanation
34. What is the maximum efficiency of pure ALOHA?
A) 50%
B) 37%
C) 18.4%
D) 25%
Show Explanation
35. What is the maximum efficiency of slotted ALOHA?
A) 18.4%
B) 36.8%
C) 50%
D) 75%
Show Explanation
36. What is a collision domain?
A) Network segment where collisions occur
B) Area covered by a broadcast
C) Physical network topology
D) Error detection mechanism
Show Explanation
37. What is a broadcast domain?
A) Area where collisions occur
B) Area where broadcast frames are propagated
C) Physical cable segment
D) Error correction area
Show Explanation
38. How do switches affect collision domains?
A) Increase collision domain size
B) Have no effect
C) Create separate collision domains
D) Eliminate all collisions
Show Explanation
39. What is the purpose of the jam signal in CSMA/CD?
A) Notify all stations of collision
B) Start data transmission
C) End data transmission
D) Synchronize stations
Show Explanation
40. What is the purpose of interframe gap in Ethernet?
A) Error detection
B) Time between frame transmissions
C) Collision detection
D) Address resolution
Show Explanation
41. What is the purpose of the preamble in an Ethernet frame?
A) Error detection
B) Address identification
C) Synchronization
D) Data compression
Show Explanation
42. What does SFD stand for in Ethernet?
A) Start Frame Delimiter
B) Synchronous Frame Data
C) Standard Frame Definition
D) Secure Frame Delivery
Show Explanation
43. What is the FCS field used for in Ethernet?
A) Frame synchronization
B) Error detection
C) Address resolution
D) Flow control
Show Explanation
44. What access method does Token Ring use?
A) CSMA/CD
B) CSMA/CA
C) Token passing
D) ALOHA
Show Explanation
45. What topology does FDDI use?
A) Dual ring
B) Star
C) Bus
D) Mesh
Show Explanation
46. What does LLC stand for in the Data Link layer?
A) Local Link Control
B) Logical Link Control
C) Link Layer Control
D) Low Level Control
Show Explanation
47. The Data Link layer is divided into which two sublayers?
A) LLC and MAC
B) Physical and Logical
C) Upper and Lower
D) Control and Data
Show Explanation
48. What does ARQ stand for?
A) Automatic Response Query
B) Advanced Request Queue
C) Automatic Repeat Request
D) Asynchronous Request Response
Show Explanation
49. What is the hidden terminal problem?
A) Terminal is physically hidden
B) Two stations cannot hear each other
C) Terminal has no power
D) Terminal is not configured
Show Explanation
50. Which mechanism is used to solve the hidden terminal problem?
A) RTS/CTS
B) CSMA/CD
C) Token passing
D) ALOHA
Show Explanation
