Source to Fiber Power Launching Photodetectors - Electronic Engineering (MCQ) questions & answers

1)   When an optical signal is incident on a photo-detector, which noise originate/s due to statistical nature of production and collection of photoelectrons?

a. Dark Current Noise
b. Quantum Noise
c. Surface Leakage Current noise
d. All of the above
Answer  Explanation 

ANSWER: Quantum Noise

Explanation:
No explanation is available for this question!


2)   Which photodiodes are crucially applicable to overcome the bandwidth-quantum efficiency trade-off along with its resemblence to the pyramid structure?

a. Mushroom Waveguide Photodiode
b. Traveling Wave Photodiode
c. Resonant Cavity Photodiode
d. All of the above
Answer  Explanation 

ANSWER: Mushroom Waveguide Photodiode

Explanation:
No explanation is available for this question!


3)   According to frequency response of photo-detector, the modulation frequency at which the output current decreases to ________of peak value.

a. one-third
b. one-fourth
c. half
d. one-tenth
Answer  Explanation 

ANSWER: half

Explanation:
No explanation is available for this question!


4)   The spectral response of an ideal photodetector depicts its efficiency as a function of _________

a. amplitude
b. frequency
c. period
d. wavelength
Answer  Explanation 

ANSWER: wavelength

Explanation:
No explanation is available for this question!


5)   In pyroelectric photodetectors, the consequent increase in dielectric constant due to temperature variation by the photon absorption, is generally measured as change in _______

a. resistance
b. inductance
c. admittance
d. capacitance
Answer  Explanation 

ANSWER: capacitance

Explanation:
No explanation is available for this question!


6)   In Lambertian output pattern of LED, the source is ______ bright from all directions.

a. Less
b. Equally
c. More
d. Unpredictably
Answer  Explanation 

ANSWER: Equally

Explanation:
No explanation is available for this question!


7)   The small section of fiber which is coupled to the optical source is known as _________

a. Flylead
b. Pigtail
c. Both a and b
d. None of the above
Answer  Explanation 

ANSWER: Both a and b

Explanation:
No explanation is available for this question!


8)   For a photo-diode with responsivity of 0.50 A/W & optical power of about 12μW, what would be the value of generated photocurrent?

a. 3 μA
b. 6 μA
c. 9 μA
d. 12 μA
Answer  Explanation 

ANSWER: 6 μA

Explanation:
No explanation is available for this question!


9)   Which among the following results in the removal of LED lens interface for achieving high coupling efficiency?

a. Spherical lens
b. Cylindrical lens
c. Integral lens LED
d. All of the above
Answer  Explanation 

ANSWER: Integral lens LED

Explanation:
No explanation is available for this question!


10)   While coupling of LEDs with fiber, on which factor/s does the size of source and lighting angle generated within the semiconductor depend/s?

a. Geometry of die
b. Refractive index of semiconductor
c. Encapsulation Medium
d. All of the above
Answer  Explanation 

ANSWER: All of the above

Explanation:
No explanation is available for this question!