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**

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**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**

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

**a) Conductor**

**b) Insulator**

**c) Semiconductor**

**d) Power regulator**

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**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**

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**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° **

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**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**

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**Q1. Answer: d**

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**Q2. Answer: a**

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**Q3. Answer: b**

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**Q4. Answer: b**

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**Q5. Answer: c**

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**Q6. Answer: b**

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**Q7. Answer: c**

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**Q8. Answer: a**

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**Q9. Answer: c**

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**Q10. Answer: a**

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**Q11. Answer: c**

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**Q12. Answer: d**

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**Q13. Answer: c**

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**Q14. Answer: a**

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**Q15. Answer: b**

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**Q16. Answer: c**

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**Q17. Answer: b**

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**Q18. Answer: b**

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**Q19. Answer: c**

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**Q20. Answer: c**