Q.1
In the design of a single mode step index optical fiber close to upper cut off, the single mode operation is NOT preserved if
  • a) Radius as well as operating wavelength are halved
  • b) Radius as well as operating wavelength are doubled
  • c) Radius is halved and operating wavelength is doubled
  • d) Radius is doubled and operating wavelength is halved
Q.2
Which parameters cannot be computed from the Smith chart?
  • a) Impedance
  • b) Admittance
  • c) Reflection coefficient and VSWR
  • d) Intrinsic impedance
Q.3
Consider a transmission line of characteristic impedanceohm. Let it be terminated at one end by +johm. The VSWR produced by it in the transmission line will be
  • a) 1
  • b) 0
  • c) Infinity
  • d) +j
Q.4
A transmission line whose characteristic impedance is a pure resistance
  • a) Must be a lossless line
  • b) Must be a distortionless line
  • c) May not be a lossless line
  • d) May be a lossless and may not be a distortionless line
Q.5
A two wire transmission line of characteristic impedance Z is connected to a load impedance ZL(ZL and Zo are not equal). Impedance matching cannot be achieved with
  • a) A quarter wavelength transformer
  • b) A half wavelength transformer
  • c) An open circuited parallel stub
  • d) A short circuited parallel stub
Q.6
A transmission line of pure resistance characteristic impedance is terminated with an unknown load. The measured value of VSWR on the line is 2 and a voltage minimum point is found to be at the load. The load impedance is then
  • a) Complex
  • b) Purely capacitive
  • c) Purely resistive
  • d) Purely inductive
Q.7
Which one of the following field patterns represents a TEM wave travelling in the positive x direction?
  • a) E = +8y, H = -4z
  • b) E = -2y, H = -3z
  • c) E = +2z, H = +2y
  • d) E = -3y, H = +4z
Q.8
The modes in a rectangular waveguide are denoted by TEmn / TMmn, where m and n are the Eigen values along the larger and smaller dimensions of the waveguide respectively. Which one of the following statements is true?
  • a) The TM10 mode does not exist
  • b) The TE10 mode does not exist
  • c) The TE10 and TM10 both exist and have same cut off frequencies
  • d) When m and n are increases, the cut off frequency decreases
Q.9
In a microwave test bench, why is the microwave signal amplitude modulated at 1 kHz?
  • a) To increase the sensitivity of measurement
  • b) To transmit the signal to a far off place
  • c) To study amplitude modulation
  • d) Because crystal detector fails at microwave frequencies
Q.10
Consider a lossless antenna with a directive gain of +6 decibel. If 1 milliwatt of power is fed to it, the total power radiated by the antenna will be (in milliwatt)
  • a) 4
  • b) 1
  • c) 7
  • d) 1/4
0 h : 0 m : 1 s