# Electromagnetic and Transmission Lines 1

Electronic Engineering MCQ Question Papers: ENTC, IT Interview Placement

Subject:  Electromagnetic and Transmission Lines 1

Part 1: List for questions and answers of Electromagnetic  & Transmission Line

Q1. The constant x-circles of Smith chart becomes smaller due to increase in the value of ‘x’ from ______

a) 0 to p

b) 0 to 2p

c) 0 to p /2

d) 0 to 8

Q2. According to Smith diagram, where should be the position of reflection coefficient value for a unity circle with unity radius?

a) On or inside the circle

b) Outside the circle

c) Both a and b

d) None of the above

Q3. If the quarter line is short-circuited, then it acts as _______

a) Conductor

b) Insulator

c) Semiconductor

d) Power regulator

Q4. After what wavelength does the nature of graph get reversed for the input impedance of open-circuited line?

a) λ /2

b) λ /4

c) λ /8

d) λ /16

Q5. What is the phase variation range for reflection coefficient in the transmission lines?

a) 0° to 90°

b) 90° to 150°

c) 0° to 180°

d) 90° to 360°

Q6. Which lossless element is inserted between source and load in addition to an ideal transformer in order to reduce the effect of reflection loss phenomenon by image matching?

a) Amplitude shifter

b) Phase shifter

c) Frequency divider

d) Voltage divider

Q7. For a transmission line with propagation constant ? = 0.650 + j 2.55, what will be the value of phase velocity for 1 kHz frequency?

a) 1.18 x 103 km/sec

b) 1.50 x 103 km/sec

c) 2.46 x 103 km/sec

d) 4.58 x 103 km/sec

Q8. What would be the depth of penetration for copper at 2 MHz frequency with s = 5.8 x 107?

a) 46.72 µm

b) 56.90 µm

c) 66.08 µm

d) 76.34 µm

Q9. The ratio of magnitudes of electric field intensity to the magnetic field intensity is regarded as ________

a) Intrinsic Impedance

b) Characteristic Impedance

c) Both a and b

d) None of the above

Q10. How is the relation between energy transfer and the electric and magnetic fields specified?

a) By Poynting theorem

b) By Stoke’s theorem

c) By Helmholtz theorem

d) By Lagrange’s theorem

Q11. According to Maxwell’s first equation in a point form for the static field, the electric flux per unit volume by leaving a small value is equal to __________

a) Zero

b) Current density

c) Volume charge density

d) Magnetic field intensity

Q12. Galvanised steel is generally used as

a) stray wire

b) earth wire

c) structural components

d) all of the above

Q13. If the medium is different than air, then what would be the equation of capacitance for a co-axial cable capacitor?

a) C = e0 er A / d

b) C = 4p e0 er [ab / a – b]

c) C = 2p e0 er L / ln (b/a)

d) C = 2p e0 er R

Q14. Which type of capacitor possesses magnitude of flux density equivalent to its surface charge density?

a) Parallel Plate capacitor

b) Spherical Capacitor

c) Co-axial cable capacitor

d) None of the above

Q15. For an estimated value of polarization (P) = 4 .42 x 10-10 c/m^2 and the availability of 4 x 10^18 dipoles/m^3, what will be the value of average dipole moment for dielectric material?

a) 0.05 x 10^-28

b) 1.105 x 10^-28

c) 1.205 x 10^-28

d) 1.405 x 10^-28

Q16. If the magnitude of E for a dielectric material is 0.12 mV/m along with electric susceptibility of about 4, what would be the magnitude of polarization?

a) 2.20 x 10^-15 c/m^2

b) 3.89 x 10^-15 c/m^2

c) 4.24 x 10^-15 c/m^2

d) 5.64 x 10^-15 c/m^2

Q17. According to the definition of dielectric strength of dielectric medium, which value of electric field give rise to an occurrence of dielectric breakdown phenomenon?

a) Maximum

b) Minimum

c) Initial

d) Final

Q18. Consider a point charge of about 10nC is located at origin. If V = 4V at (0,5,7) and point A (-6,4,12), then what would be the value of potential at point B (2,10,14)?

a) 1.261 V

b) -1.261 V

c) 2.696 V

d) -2.696 V

Q19. If a point ‘P’ has spherical coordinates (r = 5000, θ  = 0°, Ø = 0°), then what will be its equivalent value (x,y,z) in Cartesian co-ordinate system?

a) (5000, 0, 0)

b) (0, 5000, 0)

c) (0, 0, 5000)

d) (0, 0, 0)

Q20. Length of the cable is doubled, its capacitance C will be

a) one-fourth

b) one-half

c) doubled

d) unchanged

Part 1: List for questions and answers of Electromagnetic  & Transmission Line