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
Support mcqgeeks.com by disabling your adblocker.
Please disable the adBlock and continue. Thank you.