This Portion of Electrical and Electronic Instrumentation contains Automatic Process Control MCQs (Multiple Choice Questions and Answers) / Objective Type Questions and Answers.
This Section covers below lists of topics.
- Introduction
- How does an Optical Fibre Work?
- Sources and Detectors
- Fibre Optic Power Measurement
PRACTICE IT NOW TO SHARPEN YOUR CONCEPT AND KNOWLEDGE
1. Light passes through the fibre due to phenomena of
- total internal reflection
- reflection from the interface of two medium
- transmission to the second medium
- both transmission and reflection at the interface of two medium
A. total internal reflection
2. LEDs operating in the wavelength of 800–900 nm are mainly made of
- GaAs
- GaAlAs
- GaAsP
- InGaAsP
B. GaAlAs
3. The width of active region of LASER diode is comparatively
- wider that LEDs
- almost equal to LEDs
- much wider that LEDs
- narrower than LEDs
D. narrower than LEDs
4. PIN photodiodes are kept in
- forword bias
- reverse bias
- connected circuit and no bias voltages are given
- initially forword biased and then reverse biased
B. reverse bias
5. Avalanche photodiodes have output voltage comparatively
- lower that PIN photodiode
- higher than PIN photodiode
- higher than normal photodiode
- higher than normal and PIN photodiode
D. higher than normal and PIN photodiode
6. In OTDR response, the peaks of the reflected waveform do not occur due to
- reflection from the unterminated end of the fibre
- reflection from a connector
- backscatter
- reflection from the interface of core and cladding
D. reflection from the interface of core and cladding
