# Quarter Wave Transformer MCQ’s

This set of RF & Microwave Circuit Design Multiple Choice Questions & Answers (MCQs) focuses on “Quarter Wave Transformer”.

1. If a λ/4 transmission line is 100Ω is used to match a transmission line to a load of 100Ω, then the characteristic impedance of the transmission line is:

a) 100 Ω

b) 50 Ω

c) 70.71 Ω

d) 200 Ω

2. Expression for the characteristic impedance of a transmission line(λ/4) used for impedance matching is:

a) Z_{1}=√(ZₒR)L

b) Z_{1}=√(Zₒ/R)L

c) Z_{1}=√(Zₒ+R)L

d) None of the mentioned

3. If a transmission line of characteristic impedance 50 Ω is to be matched to a load of 100Ω, then the characteristic impedance of the ƛ/4 transmission line to be used is:

a) 70.71 Ω

b) 50 Ω

c) 100 Ω

d) 75 Ω

4. If there is no standing wave on a transmission line, then the value of SWR is:

a) 1

b) 0

c) Infinity

d) Insufficient data

5. For a transmission line , if the input impedance of the transmission line is 100Ω with a characteristic impedance of 150Ω, then the magnitude of the reflection co efficient:

a) 0.5

b) 1

c) 0.2

d) 0

6. When a transmission line of characteristic impedance(50Ω) zₒ is matched to a load by a λ/4 transmission line of characteristic impedance 100Ω, then the transmission co efficient is:

a) 1.5

b) 0.5

c) 1.333

d) 2

7. When a λ/4 transmission line is used for impedance matching, then which of the following is valid?

a) Standing waves are present on the λ/4 transmission line

b) No standing waves on the λ/4 transmission line

c) Standing waves are not present both on the feed line and the matching λ/4 line

d) Standing waves are present on both the feed line and the matching λ/4 line

8. If the reflection co-efficient of a transmission line is 0.334 with a characteristic impedance of 50Ω then the input impedance of the transmission line is:

a) 100 Ω

b) 50 Ω

c) 150 Ω

d) None of the mentioned

9. If a transmission line of zₒ=50Ω is matched using λ/4 transmission line of z₁=100Ω, then the transmission co efficient T₂ is:

a) 1

b) 0.6667

c) 1.3333

d) 2

10. If the transmission co-efficient T₁ of a transmission line is 1.333 and the characteristic impedance of the λ/4 transmission line used is 100Ω, then the characteristic impedance of the transmission line is:

a) 50Ω

b) 100Ω

c) 70.71Ω

d) None of the mentioned