Electromagnetic Theory and Transmission Lines Mid - II, April - 2012

1.For normal incidence of the wave on perfect conductor
  • Surface current doesn’t exist
  • surface exists
  • conducting current exiasts
  • free charge exists on the surface
Answer: B
2.A standing wave
  • Progresses with less than light velocity
  • progresses with more than light velocity
  • progresses with equal to light velocity
  • does not progress
Answer: D
3.The range of reflection coefficient is
  • 0 to 1
  • 0 to infinity
  • -1 to 1
  • 1 to infinity
Answer: C
4.Electric and magnetic fields which are parallel
  • Constitute power flow
  • constitute infinite power flow
  • constitute unit magnitude power flow
  • no power flow
Answer: D
5.The propagation velocity of TE waves
  • Depends on frequency
  • independent of frequency
  • depends on square of frequency
  • varies inversely with frequency
Answer: A
6.As per the boundary condition,
  • The normal component of E is continuous across the boundary.
  • The tangential component of E is continuous across the boundary.
  • The tangential component of D is continuous across the boundary.
  • The normal component of H is continuous across the boundary
Answer: B
7.The magnetic field at the surface of a good conductor is 2A/m. The frequency of the field is 600 MHz. The surface r.m.s current density is
  • 0.5 A/m
  • 0.5 A/m2
  • 2 A/m
  • 2 A/m2
Answer: C
8.If the reflection coefficient is -1/2 then the swr is
  • Zero
  • one
  • 1/3
  • 3
Answer: D
9.The wave impedance over the cross section of wave guide
  • Increases with frequency
  • decreases with frequency
  • increases exponentially
  • constant
Answer: D
10.Hysteresis and eddy current losses in loading coils leads to
  • Increase in L
  • Decrease in L
  • Increase in R
  • decrease in R
Answer: C
11.The frequency at which the wave motion ceases is called __________.
Answer: Cutoff frequency.
12.A Lumped load line behaves as a _____.
Answer: Low pass filter.
13.By inserting inductance in series with the line to increase the inductance is called _______.
Answer: Loading.
14.One neper is = ___________.
Answer: 8.68 dB.
15.A short circuited λ/4 line can be used a __________.
Answer: Insulator.
16.The range of UHF is ___________ to _________.
Answer: 300 MHz to 3 GHz.
17.The loading practice is generally restricted to _______ only.
Answer: Cables.
18.When a transmission line is shorted, the first voltage minimum occurs at _________.
Answer: Load.
19.The center of smith chart represents ___________.
Answer: Matched load impedence.
20.Attenuation factor of TEM wave is proportional to ______ of frequency.
Answer: Square root.