This set of RF & Microwave Circuit Design Multiple Choice Questions & Answers (MCQs) focuses on “Co-axial Lines Field Analysis”.

1. Expression for resistance R of a coaxial transmission line outer radius b and inner radius a is:

a) R_{s}/2π ( 1/a+1/b)

b) 2πω∈”/ln(b/a)

c) μ/π cos^{-1}(b/a)

d) πϵ’/cosh^{-1}(b/a)

2. If the outer and the inner diameter of a coaxial transmission line are 20 mm and 10 mm respectively, then the inductance /m of the transmission line is:

a) 0.13 µH

b) 0.2 µH

c) 0.3 µH

d) 0.1 µH

3. The expression for conductance G of a coaxial transmission line with outer radius ‘b’ and inner radius ‘a’ is given by:

a) 2πωε”/ (ln b/a)

b) (R/2π)(1/a+1/b)

c) Rb/πa

d) 2Rb/a

4. If the outer circumference and the inner circumference of a transmission line are 40π and 25π units respectively, then the capacitive reactance of the coaxial transmission line is:

a) 0.376 nF

b) 0.45 nF

c) 0.9 nF

d) none of the mentioned

5. Characteristics impedance of a coaxial line with external and inner diameter 5mm is:

a) 40 Ω

b) 41.58 Ω

c) 47.78 Ω

d) 54.87 Ω

6. Flow of power in transmission line takes place through:

a) Electric field and magnetic field

b) Voltage and current

c) Voltage

d) Electric field

7. For a 2 wire transmission line, if the complex part of permittivity is 2.5, then the given distance between the 2 wires is 10mm and operated at a frequency of 1.2 MHz and the radius of the line being 5mm, then the conductance of the transmission line is:

a) 0.2 µH

b) 0.1 µH

c) 0.5 µH

d) 1 µH

8. The characteristic impedance of the transmission line if the outer diameter and inner diameter of the transmission line is 20 mm and 10 mm respectively, given the intrinsic impedance of the medium is 377 Ω, then the characteristic impedance of the transmission line is:

a) 41.58 Ω

b) 50 Ω

c) 377 Ω

d) None of the mentioned

9. When a transmission line is exited by a source, total power supplied is delivered to the load.

a) True

b) False

10. Expression for propagation constant. γ In terms of ω is:

a) √ω^{2}µ∈

b) ω^{2}µ∈

c) – ω^{2}µ∈

d) None of the mentioned