MCQ on Fiber Optic Devices & Instrumentation

Multiple Choice Questions on Fiber Optic Devices & Instrumentation

A pn-junction diode emits light by spontaneous emission
(a) LED
(b) APD
(c) PIN diode
(d) Zener diode

Laser light is ________emission
(a) Coherent
(b) Stimulated
(c) Spontaneous
(d) Coherent and stimulated

Which of the following is the fastest light sensor?
(a) PIN photodiode
(b) Photovoltaic diode
(c) Phototransistor
(d) Avalanche photodiode

The _____of a detector is the fraction of incident photons that produce a photoelectron or electron-hole pair
(a) Rsponsitivity
(b) Photon efficiency
(c) Aperture
(d) Quantum efficiency

The __________is equql to the number of electrons emitted per second times the electron charge
(a) intensity
(b) optical power
(c) photocurrent
(d) responsitivity

A measure of conversion efficiency of a photo detector
(a) Efficiency
(b) Responsitivity
(c) Dark current
(d) Spectral response

The leakage current that flows through a photodiode with no light input
(a) dark voltage
(b) dark impedance
(c) dark power
(d) dark current

What is the lifetime of LEDs?
(a) 200,000 minutes
(b) 200,000 hours
(c) 150,000 minutes
(d) 100,000 hours

Photodiodes used as fiber optic directors are
(a) Unbiased to generate a voltage same as a solar cell
(b) Foward bias
(c) Reversed bias
(d) Thermoelectrically cooled