Unit 3 - Practice Quiz

1 What is the fundamental physical principle behind the propagation of light in an optical fiber?

2 In an optical fiber, what is the relationship between the refractive index of the core () and the refractive index of the cladding ()?

3 Which component of the optical fiber provides mechanical strength and protects the core-cladding structure?

4 The critical angle at the core-cladding interface is given by which formula?

5 What is the 'Acceptance Angle' of an optical fiber?

6 The Numerical Aperture (NA) of a fiber is a measure of its:

7 Which of the following is the correct formula for Numerical Aperture (NA) assuming air () is the launch medium?

8 The Relative Refractive Index Difference () is defined as:

9 How is the Numerical Aperture (NA) related to the Relative Refractive Index Difference ()?

10 If the refractive index of the core is 1.50 and the cladding is 1.48, what is the Numerical Aperture (approximate)?

11 The V-number (or normalized frequency) determines:

12 What is the formula for the V-number?

13 What is the condition for a Step Index fiber to be Single Mode?

14 Approximately how many modes () travel in a Step Index Multimode fiber if is large?

15 Approximately how many modes () travel in a Graded Index (parabolic profile) Multimode fiber?

16 In a Step Index fiber, the refractive index:

17 In a Graded Index (GRIN) fiber, the light rays travel in:

18 Why are Graded Index fibers preferred over Step Index Multimode fibers for higher bandwidth applications?

19 What is the typical core diameter of a Single Mode Fiber (SMF)?

20 Attenuation in an optical fiber is usually expressed in:

21 If the input power is and output power is over a length , the attenuation (in dB/km) is calculated as:

22 Rayleigh scattering loss is inversely proportional to:

23 Which of the following causes Intrinsic Absorption in optical fibers?

24 The peak absorption around 1.38 m in silica fibers is primarily caused by:

25 Microbending loss is caused by:

26 Which type of dispersion is dominant in Single Mode Fibers?

27 Material dispersion arises because:

28 What is the primary advantage of operating at the 1550 nm wavelength window?

29 Intermodal dispersion leads to:

30 Which rays propagate through the fiber axis without reflecting?

31 Skew rays are rays that:

32 Why is an optical fiber considered a 'Dielectric Waveguide'?

33 If the fractional refractive index change and , what is ?

34 Macrobending loss can be reduced by:

35 What is the unit of the V-number?

36 Waveguide dispersion depends primarily on:

37 Which window of optical communication is typically around 850 nm?

38 What is the phenomenon responsible for the 'Zero Dispersion Wavelength'?

39 In the context of fiber optics, what does 'Modes' refer to?

40 If a fiber has an acceptance angle of , light entering at will:

41 For a Multimode Step Index fiber, if the core radius is doubled, the number of modes increases by a factor of:

42 The refractive index profile of a Graded Index fiber is typically:

43 Which of the following is NOT a source of loss in optical fibers?

44 Which fiber type has the largest information-carrying capacity (Bandwidth)?

45 The cone of acceptance is the solid angle formed by rotating the:

46 If light travels from air () into a fiber core (), the maximum value of NA is theoretically:

47 Why are optical fibers immune to Electromagnetic Interference (EMI)?

48 Calculate the acceptance angle if the Numerical Aperture is 0.5 and the medium is air.

49 As the wavelength of light increases, the V-number of the fiber:

50 Dispersion is usually measured in units of: