Transline and Antenna System (Final Quiz)

He was considered the "Father of Fiber Optics" who coined the term in 1956.

• ACS van Heel

• NS Kapany

• H Lamm

• AL Schawlow

Answer explanation

A.C.S van Heel of Holland and H.H. Hopkins and

N.S. Kapany of England experimented with light  transmission through bundles of fibers. Their studies led to the development of the  flexible fiberscope, which is used extensively in  the medical field.

It was Kapany who coined the term  “fiber optics” in 1956.

A device built by Theodore Maiman that produces and amplifies electromagnetic radiation mainly in the microwave region of the frequency spectrum.

• Laser

• Maser

• Photophone

• Fiberscope

Answer explanation

Theodore H. Maiman, a scientist with Hughes Aircraft  Company, built the first optical maser.

Maser is a device that produces and amplifies  electromagnetic radiation mainly in the microwave region  of the spectrum.

Why do you think fiber optic cables are immune to crosstalk?

• Fiber cables are typically used in high-bandwidth applications, which eliminates crossing the information from one channel to another.

• Fiber cables only allow light to pass through. It is immune to EMI caused by lightning, electric motors, relays, among others.

• Fiber cables are not surrounded by magnetic field; therefore, it does not affect its adjacent cables.

• Not true! Fiber optic cables are also affected by crosstalk the way metallic cables are.

Answer explanation

•Glass and plastic fibers are nonconductors of electrical  current;

•Therefore, fiber cables are not surrounded by a changing  magnetic field, which is the primary cause of crosstalk  between metallic conductors located physically close to  each other.

Which of the following is NOT a disadvantage of optical fiber cables?

• Requires wider bandwidth

• Requires remote electrical power

• Expensive tools, equipment, and training

• Interfacing cost

• Strength

Answer explanation

The disadvantages of optical fibers include the following:

1. 1. Interfacing cost

2. 2. Strength

3. 3. Remote electrical power

4. 4. Optical fiber cables are more susceptible to losses introduced by bending the cable

5. 5. Specialized tools, equipment, and training

In order to have an effective and useful fiber optic cable, which of the following conditions must be met? (Assume n_clad and n_core to be refractive indices of the cladding and core, respectively)

• n_clad + n_core = 2.50

• n_clad = n_core

• n_clad > n_core

• n_clad < n_core

Answer explanation

An optical fiber is essentially a waveguide for light (usually  infrared). It consists of a core and cladding that surrounds  the core. Both are made of transparent material, either  glass or plastic, but the index of refraction of the cladding  is less than that of the core, causing rays of light leaving  the core to be refracted back in the core, so that the light  propagates down the fiber.

High humidity in exposed fiber optic cables can cause a detrimental phenomenon called ____.

• stress corrosion

• moisture

• erosion

• breakpoint

A branch of science which deals with visible light waves and its related measurements.

• Radiometry

• Optometry

• Photometry

• Fibroscopy

Which of the following is NOT an SI Unit?

• Lux

• Lumen

• Candela

• Watt/sq.meter

• Maxwell

It represents the amount of light bending as it passes from one material to another; it is represented by the ratio of the speed of light in vacuum to the speed of light as it travels through a solid material (like glass).

• bending ratio

• refractive index

• velocity factor

• numerical aperture

_____ is the angle at which the propagating ray strikes the interface with respect to the normal.

• Angle of strike

• Angle of refraction

• Angle of incidence

• Angle of reflection