Basics of transmission lines MCQs January 8, 2026November 20, 2024 by u930973931_answers 20 min Score: 0 Attempted: 0/20 Subscribe 1. A transmission line is used to: (A) Amplify electrical signals (B) Store electrical energy (C) Transmit electrical power or signals between two locations (D) Convert analog signals to digital signals 2. Which of the following is an example of a transmission line? (A) All of the above (B) Optical fiber (C) Twisted pair cable (D) Coaxial cable 3. The primary purpose of a transmission line is to: (A) Match impedance (B) Deliver signals with minimal loss (C) Increase bandwidth (D) Suppress noise 4. Which parameter represents the opposition to current flow in a transmission line? (A) Inductance (B) Capacitance (C) Conductance (D) Resistance 5. What does the characteristic impedance (Z₀) of a transmission line depend on? (A) Resistance and conductance (B) Voltage and current (C) Inductance and capacitance per unit length (D) Frequency and wavelength 6. What is the unit of characteristic impedance? (A) Henry (B) Farad (C) Ohm (D) Siemens 7. For a lossless transmission line, the characteristic impedance is given by: (A) √(R/G) (B) √(G/L) (C) √(RC) (D) √(L/C) 8. The velocity of propagation in a transmission line is given by: (A) v = 1/√(LC) (B) v = √(LC) (C) v = 1/RC (D) v = √(L/C) 9. Standing waves are formed in a transmission line when: (A) Impedance is matched (B) The frequency of the source matches the load (C) Power is transmitted efficiently (D) There is a reflection due to impedance mismatch 10. The standing wave ratio (SWR) is a measure of: (A) Signal strength (B) Power loss (C) Frequency response (D) Impedance matching 11. Which of the following is NOT a type of transmission line? (A) Coaxial cable (B) Rectifier line (C) Parallel plate line (D) Microstrip line 12. Twisted pair cables are commonly used for: (A) Satellite communication (B) Audio frequency signals (C) High-power transmission (D) Telephone and Ethernet networks 13. Which type of transmission line is best suited for high-frequency applications? (A) Coaxial cable (B) Waveguide (C) Twisted pair cable (D) Open wire line 14. The primary causes of power loss in a transmission line are: (A) Reflections and harmonics (B) Resistance of conductors and dielectric losses (C) Impedance matching and phase shift (D) Capacitance and inductance 15. What is the term for power loss due to electromagnetic radiation from a transmission line? (A) Dielectric loss (B) Radiation loss (C) Copper loss (D) Standing wave loss 16. Impedance matching is important in transmission lines to: (A) Minimize reflections and maximize power transfer (B) Reduce the frequency of the signal (C) Increase the signal voltage (D) Eliminate standing waves 17. A quarter-wave transformer is used to: (A) Increase the bandwidth (B) Match two different impedances (C) Eliminate noise in a transmission line (D) Reduce the attenuation of a signal 18. In a transmission line, a Smith chart is used to: (A) Analyze impedance and reflection coefficients (B) Plot the gain of the system (C) Measure voltage standing wave ratio (VSWR) (D) Calculate the attenuation constant 19. A lossless transmission line has: (A) Infinite reflection coefficient (B) Zero inductance and capacitance (C) Maximum attenuation (D) Zero resistance and conductance 20. The term “cutoff frequency” in a waveguide or transmission line refers to: (A) The maximum frequency that can propagate (B) The frequency at which impedance is zero (C) The frequency at which reflections are minimized (D) The minimum frequency below which no propagation occurs