Description : The _____ of a detector is the fraction of incident photons that produce a photoelectron or electron-hole pair ∙ a. Responsitivity ∙ b. Photon efficiency ∙ c. Aperture ∙ d. Quantum efficiency
Last Answer : d. Quantum efficiency
Description : The law that states “When visible light of high frequency electromagnetic radiation illuminates a metallic surface, electrons are emitted” is known as ____________. ∙ A. Einstein law of photon ∙ B. Marconi’s law ∙ C. Maxwell’s law ∙ D. Plank’s law
Last Answer : D. Plank’s law
Description : Which of the following terms best describes the reason that light is refracted at different angles? ∙ A. Photon energy changes with wavelength ∙ B. Light is refracted as a function of surface smoothness ∙ ... determined partly by a and b ∙ D. The angle is determined by the index of the materials
Last Answer : ∙ D. The angle is determined by the index of the materials
Description : Optical detectors are square-law devices because they respond to _____ rather than amplitude ∙ a. Intensity ∙ b. Light ∙ c. Density ∙ d. Photon
Last Answer : a. Intensity
Description : The quantum of light is called the ____________________.
Last Answer : photon
Description : Which theory states that the light wave behaves as if it consists of many tiny particles? ∙ a. Huygen’s theory ∙ b. Wave theory of light ∙ c. Nyquist theory ∙ d. Quantum theory
Last Answer : ∙ d. Quantum theory
Description : The energy of the photon is ∙ a. Directly proportional to its bandwidth ∙ b. Directly proportional to the Planck’s constant ∙ c. Directly proportional to Boltzmann’s constant ∙ d. Inversely proportional to the Planck’s constant
Last Answer : Directly proportional to the Planck’s constant
Description : What is the photon energy for an infrared wave with frequency of 1012 Hz? ∙ a. 10.6 x 1034 joules ∙ b. 6.63 x 10-34 joules ∙ c. 6.63 x 10-22 joules ∙ d. 10.6 x 1022 joules
Last Answer : ∙ c. 6.63 x 10-22 joules
Description : A packet of energy which is equal to the difference between the two energy levels. ∙ A. Photons ∙ B. Electronvolt ∙ C. Quantum ∙ D. Quanta
Last Answer : A. Photons
Description : Photon is the fundamental unit/ quantum of – (1) gravitation (2) electricity (3) magnetism (4) light
Last Answer : (4) light Explanation: A photon is an elementary particle, the quantum of light and all other forms of electromagnetic radiation. The modern photon concept was developed gradually by Albert Einstein.
Description : Photon is the fundamental unit/ quantum of (1) gravitation (2) electricity (3) magnetism (4) light
Last Answer : light
Description : A hydrogen like atom with atomic number Z is in an excited state of quantum number 2n. It can emit a maximum energy photon of 204 eV. If it makes a tr
Last Answer : A hydrogen like atom with atomic number Z is in an excited state of quantum number 2n. It can emit a ... state energy of hydrogen atom is - 13. 6 eV.
Description : What is the difference between Quantum and photon?
Last Answer : Ans. The smallest packet of Energy of any radiation is called as Quantum and that of Light is known as Photon.
Description : PAR (Photo-synthetically active radiation) is measured in (A)Photon (B) Watts (C) Einstein (D) Quantum
Last Answer : (C) Einstein
Description : In a PIN diode, leakage current in the absence of light is called: a. baseline current b. zero-point current c. dark current d. E-H current
Last Answer : c. dark current
Description : The ratio of the speed of light in air to the speed of light in another substance is called ∙ A. speed factor ∙ B. index of reflection ∙ C. index of refraction ∙ D. speed gain
Last Answer : ∙ B. index of reflection
Description : Single frequency light is called ∙ A. pure ∙ B. intense ∙ C. coherent ∙ D. monochromatic
Last Answer : D. monochromatic
Description : Single-frequency light is called ∙ a. Pure ∙ b. Intense ∙ c. Coherent ∙ d. Monochromatic
Last Answer : d. Monochromatic
Description : The ratio of speed of light in air to the speed of light in another substance is called the ∙ a. Speed factor ∙ b. Index of reflection ∙ c. Index of refraction ∙ d. Dielectric constant
Last Answer : b. Index of reflection
Description : The loss in signal power as light travels down a fiber is called ∙ a. Dispersion ∙ b. Scattering ∙ c. Absorption ∙ d. Attenuation
Last Answer : ∙ d. Attenuation
Description : Dense ____________________ allows many different wavelengths of light to share a cable.
Last Answer : WDM
Description : For safety, you should never ____________________ at the end of an optical fiber unless you know it is not connected to a light source.
Last Answer : look
Description : A ____________________ diode is the usual light detector for single-mode
Last Answer : PIN
Description : A ____________________ diode is the usual light source for single-mode cable.
Last Answer : laser
Description : A ____________________ is a short length of fiber that carries the light away from the source
Last Answer : pigtail
Description : With optical fiber, ____________________ light is more common than visible light.
Last Answer : infrared
Description : Refraction is the ∙ A. bending of light ∙ B. reflection of light waves ∙ C. distortion of light waves ∙ D. diffusion of light waves
Last Answer : A. bending of light
Description : The main benefit of light wave communications over microwaves or any other communications media are ∙ A. lower cost ∙ B. better security ∙ C. wider bandwidth ∙ D. freedom from interface
Last Answer : C. wider bandwidth
Description : EMD is best described by which statement? ∙ A. 70 percent of the core diameter and 70% of the fiber NA should be filled with light. ∙ B. 70 percent of the fiber diameter and 70% of the ... be measured at the output. ∙ D. 70 percent of the unwanted wavelengths should be attenuated by the fiber.
Last Answer : 70 percent of the core diameter and 70% of the fiber NA should be filled with light.
Description : The speed of light in plastic compared to the speed of light in air is ∙ A. less ∙ B. more ∙ C. the same ∙ D. zero
Last Answer : A. less
Description : The upper pulse rate and information-carrying capacity of a cable is limited by ∙ A. pulse shortening ∙ B. attenuation ∙ C. light leakage ∙ D. modal dispersion
Last Answer : D. modal dispersion
Description : Total internal reflection takes place if the light ray strikes the interface at an angle with what relationship to the critical angle? ∙ A. less than ∙ B. greater than ∙ C. equal to ∙ D. zero
Last Answer : ∙ B. greater than
Description : A popular light wavelength fiber-optic cable is ∙ A. 0.7 micrometer ∙ B. 1.3 micrometer ∙ C. 1.5 micrometer ∙ D. 1.8 micrometer
Last Answer : B. 1.3 micrometer
Description : The minimum optical power a light detector can receive and still produce a usable electrical output signal. ∙ A. light responsivity ∙ B. light sensitivity ∙ C. light collectivity ∙ D. illumination
Last Answer : B. light sensitivity
Description : The term responsivity as it applies to a light detector is best described as ∙ A. the time required for the signal to go from 10 to 90 percent of maximum amplitude ∙ B. the ratio of the diode ... . the ratio of the input power to output power ∙ D. the ratio of output current to input current
Last Answer : the ratio of the diode output current to the input optical power
Description : The time it takes a light induced carrier travel across the depletion region of the semiconductor. ∙ A. dispersion ∙ B. response time ∙ C. irradiance ∙ D. transit time
Last Answer : D. transit time
Description : The leakage current that flows through a photodiode with no light input ∙ A. dark voltage ∙ B. dark impedance ∙ C. dark power ∙ D. dark current
Last Answer : D. dark current
Description : A pn-junction diode emits light by spontaneous emission ∙ A. LED ∙ B. APD ∙ C. PIN
Last Answer : A. LED
Description : How can modal dispersion reduced entirely? ∙ A. Use a graded index fiber ∙ B. Use a single-mode fiber ∙ C. Use a monochromatic light source ∙ D. Use a very sensitive light detector
Last Answer : Use a single-mode fiber
Description : It is caused by the difference in the propagation time of light rays that take different paths down the fiber. ∙ A. modal dispersion ∙ B. microbending ∙ C. Rayleigh scattering ∙ D. chromatic dispersion
Last Answer : A. modal dispersion
Description : As light is coupled in a multiport deflective device, the power is reduced by ∙ A. 1.5 dB ∙ B. 0.1 dB ∙ C. 0.5 dB ∙ D. 0.001 dB
Last Answer : C. 0.5 dB
Description : Chromatic dispersion can be eliminated by __________. ∙ A. using a monochromatic light source ∙ B. using a very small numerical aperture fiber ∙ C. using a graded-index fiber ∙ D. using a very sensitive photo detector
Last Answer : A. using a monochromatic light source
Description : Light rays that are emitted simultaneously from an LED and propagated down an optical fiber do not arrive at the far end of the fiber at the same time results to ∙ A. intramodal dispersion ∙ B. pulse length dispersion ∙ C. modal dispersion ∙ D. wavelength dispersion
Last Answer : D. wavelength dispersion
Description : For a single mode optical cable with 0.25 dB/km loss, determine the optical power 100 km from a 0.1-mW light source. ∙ A. -45 dBm ∙ B. -15 dBm ∙ C. -35 dBm
Last Answer : ∙ C. -35 dBm
Description : It is caused by hydroxide ions in the material ∙ A. visible light absorption ∙ B. infrared absorption ∙ C. ultraviolet absorption ∙ D. ion resonance absorption
Last Answer : D. ion resonance absorption
Description : t is a result of photons of light that are absorbed by the atoms of the glass core molecule. ∙ A. ion resonance absorption ∙ B. infrared absorption ∙ C. ultraviolet absorption ∙ D. visible light absorption
Last Answer : B. infrared absorption
Description : It is caused by valence electrons in the silica material from which the fiber are manufactured. ∙ A. ion resonance absorption ∙ B. infrared absorption ∙ C. ultraviolet absorption ∙ D. visible light absorption
Last Answer : ultraviolet absorption
Description : It is analogous to power dissipation to copper cables, impurities in the fiber absorb the light and covert it to heat. ∙ A. power loss ∙ B. absorption loss ∙ C. resistive loss ∙ D. heat loss
Last Answer : B. absorption loss
Description : Which of the following is not a factor in cable light loss? ∙ A. reflection ∙ B. absorption ∙ C. scattering ∙ D. dispersion
Last Answer : A. reflection
Description : Results in reduction in the power of light wave as it travels down the cable. ∙ A. power loss ∙ B. absorption loss ∙ C. resistive loss ∙ D. heat loss
Last Answer : A. power loss