With respect to computer networks, which of the following is the correct expanded form of RJ 45 ?
With respect to computer networks, which of the following is the correct expanded form of RJ 45 ?
Options
Official answer
Correct option: (D) Registered Jack 45
RJ 45 is a standard 8-pin connector used to terminate twisted-pair Ethernet cables for wired LAN connections.
Marking scheme
- 1.1 mark for selecting option (D) Registered Jack 45; no partial marks in MCQ.
Hint
RJ stands for a type of standardized connector plug — think 'Jack', not 'Jockey' or 'Radio'.
Quick oral answer
RJ 45 stands for Registered Jack 45 — an 8-pin connector used to terminate twisted-pair Ethernet cables for LAN connections.
Common mistakes
- 1.Confusing 'Jack' with 'Jockey' due to similar sound, leading students to pick option (B).
- 2.Assuming RJ relates to 'Radio' because of wireless-networking associations, leading to options (A) or (C).
Analysis and explanation
RJ 45 is one of the most common physical-layer connectors used in wired networking, and CBSE frequently tests its expanded form as a factual recall question.
Why (D) is correct
- RJ stands for Registered Jack, a standardized telecommunication network interface connector design.
- '45' identifies the specific 8-pin/8-position (8P8C) connector interface number.
- RJ 45 connectors terminate twisted-pair cables (UTP/STP) that connect computers, switches, and routers in a LAN.
Why the distractors are wrong
- (A) Radio Jockey 45 — 'Radio Jockey' is an unrelated broadcasting term, not a networking term.
- (B) Registered Jockey 45 — mixes the correct word 'Registered' with the incorrect word 'Jockey' instead of 'Jack'.
- (C) Radio Jack 45 — uses 'Radio' instead of 'Registered', which is factually incorrect.
Interesting facts
RJ 45 is standardized under US telecommunications registration standards, originally developed for telephone wiring jacks before being adapted for Ethernet.
RJ 45 connectors have 8 pins/positions (8P8C) and are used with Category 5e/6/6a Ethernet cables capable of speeds up to 10 Gbps.
Question details
Q17 of 48 questions
- Board
- CBSE
- Class
- Class 12
- Subject
- Computer Science
- Year
- 2026
- Section
- Section A
- Marks
- 1
- Type
- MCQ
- Chapter
- Computer Networks
- Topic
- RJ-45 Connector
- Bloom's level
- remember
- Syllabus topic
- Unit 2: Computer Networks — Network Cables and Connectors (RJ-45)
- Author
- CBSE
- Reviewed by
- Padhantu Academic Team
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Frequently asked questions
What does RJ stand for in RJ 45?
RJ stands for 'Registered Jack', a standardized network interface connector design.
What cable is used with an RJ 45 connector?
RJ 45 connectors are used to terminate twisted-pair cables such as Cat 5, Cat 5e, and Cat 6 Ethernet cables used in LAN wiring.