Discussion
Assertion (A) : Graded index optical fibers are used for reasonably high band width application.
Reason (R) : Graded index fibers are designed to have low time dispersion.
Answer: A
The answer is both (A) and (R) are true and (R) is the correct explanation of (A).
In a step-index multimode fiber, rays travelling at steep angles cover a longer path than axial rays and arrive later, spreading each pulse (modal or intermodal dispersion) and limiting bandwidth. A graded-index fiber has a refractive index that falls gradually from the core axis outward, so the longer outer paths are travelled faster. Arrival times equalise and time dispersion is low.
Low dispersion means pulses can be sent closer together, which is what gives the reasonably high bandwidth, so R is exactly the reason for A.
Post your comment
Please log in or register to post a comment.
Examination Categories
- SSC Exams
- Banking Exams
- Teaching Exams
- Civil Services Exams
- Railways Exams
- Engineering Recruitment Exams
- Defence Exams
- State Government Exams
- Police Exams
- Insurance Exams
- Nursing Exams
- Other Government Exams
- NRA CET
- PG Entrance Exams
- Campus Placement
- MBA Entrance Exams
- CUET and UG Entrance
- Judiciary Exams
- Regulatory Body Exams
- Software Development