Transmission Line Parameters Quiz

What is the formula for group velocity and phase velocity?

$v_g = c/\sqrt{1 - (2a)}$, $v_p = c/\sqrt{1 - (fc)}$
$v_g = c\sqrt{1 - (2a)}$, $v_p = c\sqrt{1 - (fc)}$
$v_g = c/2$, $v_p = f^2$
$v_g = c$, $v_p = f\lambda$ (correct)

What does the cutoff frequency represent in waveguide theory?

The frequency at which the phase velocity equals the speed of light.
The frequency at which the group velocity becomes half of the speed of light.
The frequency at which no higher modes can propagate through the waveguide. (correct)
The frequency at which light enters the waveguide.

What is the characteristic impedance of a waveguide?

$377 \sqrt{1-(fc)}$ (correct)
$377\sqrt{1-( \lambda ) / 2a}$
$377 / 2 \sqrt{1-(fc)}$
$377 / 2 \sqrt{1-( \lambda ) / 2a}$

What are the key components of an optical fiber?

Core, Cladding, Coating, Buffer (A) Signup and view all the answers

In optical fiber systems, what type of transmission is more common?

Digital transmission (B) Signup and view all the answers

In which band do optical fiber systems generally operate?

Infrared band (C) Signup and view all the answers

What is the velocity factor?

The ratio of the actual velocity of propagation through a vacuum to the speed of light (D) Signup and view all the answers

What is the characteristic impedance (Zo) of an infinitely long transmission line at radio frequencies?

Resistive and equal to Zo (C) Signup and view all the answers

What type of transmission line is described as nonresonant?

A line where electromagnetic waves travel without reflections (B) Signup and view all the answers

What is the relationship between voltage and current at any point along a nonresonant transmission line?

The voltage and current are in phase, and their ratio is equal to Zo (D) Signup and view all the answers

What is the propagation delay in networking applications?

The time required for a signal to travel from one end of a circuit to the other (A) Signup and view all the answers

Which statement about line losses on a nonresonant transmission line is true?

Line losses are minimum per unit length (A) Signup and view all the answers

What advantage do laser diodes have over LEDs in terms of light production?

Producing light in a narrow cone suitable for optical fiber coupling (B) Signup and view all the answers

Why are laser diodes more difficult to operate compared to LEDs?

Their current must be carefully controlled (B) Signup and view all the answers

How are lasers usually modulated?

By changing the current from just below lasing threshold to a higher value (B) Signup and view all the answers

Which of the following is true about single-mode fiber?

It has a small core diameter to support only the axial mode. (C) Signup and view all the answers

Which type of practical light detector is commonly used in fiberoptic communications receivers?

PIN Diodes (A) Signup and view all the answers

What is the advantage of multimode graded index fiber over multimode step index fiber?

It minimizes modal dispersion by varying the refractive index of the core. (D) Signup and view all the answers

Which type of fiber optic cable has higher order modes?

Both multimode step index and multimode graded index fibers (D) Signup and view all the answers

What determines the responsivity of an optical detector?

The output photocurrent (A) Signup and view all the answers

What materials are commonly used in optical detectors for different wavelengths in fiberoptic communications?

Si, GaAs, Ge, InP, InGaAs (D) Signup and view all the answers

Which component of a fiber optic system is typically more expensive for multimode fiber compared to single-mode fiber?

The transmitter and receiver equipment (D) Signup and view all the answers

What is the primary cause of higher attenuation in multimode fibers compared to single-mode fibers?

The increased scattering of light due to dopants in the glass (C) Signup and view all the answers

Which factor does the attenuation of light through glass depend on?

The wavelength of light (B) Signup and view all the answers

Which of the following is NOT a typical loss in optical fiber links?

Amplifier losses (A) Signup and view all the answers

What is the purpose of a link budget calculation in fiber optic communication systems?

To assess the overall performance and reliability of the system (A) Signup and view all the answers

Which of the following losses is NOT included in a link budget calculation?

Amplifier gain (B) Signup and view all the answers

What is the term used to describe the excess power remaining after accounting for all losses in a link budget calculation?

System margin (D) Signup and view all the answers

Which of the following is NOT a type of FTTX architecture mentioned in the text?

Fiber to the building (FTTB) (C) Signup and view all the answers

What is the simplest way to prepare a loss budget, according to the text?

Start with the transmitter power in dBm, subtract all losses in decibels, and compare the result with the required power at the receiver (D) Signup and view all the answers