1. If the dielectric material used between the grounded plates of a stripline is 2.2, when the strip line operating at 8 GHz, the wavelength on stripline is:
a) 1.2 cm
b) 2.52 cm
c) 0.15 cm
d) 3.2 cm
Explanation: The propagating wavelength on the stripline is defined by the relation C/f√∈r. substituting in the above relation, the propagating wavelength on the microstrip line is 2.52 cm.
2. Fields of TEM mode on strip line must satisfy:
a) Laplace’s equation
b) Ampere’s circuital law
c) Gaussian law
d) None of the mentioned
Explanation: If φ(x,y) is the function of potential in the stripline varying along the width and thickness, this potential function must satisfy the Laplace’s equation.
3. The one below among others is not a type TEM line used in microwave networks:
a) Co-axial wire
b) Micro strip line
c) Strip lines
d) Surface guide
Explanation: Coaxial micro strip and strip lines all support TEM mode of propagation through them. But surface guides do not support TEM mode of propagation in them. Hence it cannot be called a TEM line.
4. The one below is the only micro wave network element that is a TEM line:
a) Co-axial cable
b) Rectangular wave guide
c) Circular wave guide
d) Surface wave guide
Explanation: Coaxial cables support TEM mode of propagation in them and rectangular waveguide, circular wave guide, surface waveguides do not support TEM mode of propagation in them.
5. The relation between voltage, current and impedance matrices of a microwave network is:
a) [V] = [Z][I]
b) [Z] = [V][I]
c) [I] = [Z][V]
d) [V] = [Z]-[I]
Explanation: In microwave networks, at any point in a network, the voltage at a point is the product of the impedance at that point and current measured. This can be represented in the form of a matrix.
6. The relation between voltage, current and admittance matrices of a microwave network is:
a) [I] = [Y] [V]
b) [Y] = [V] [I]
c) [I] = [Z] [V]
d) [V] = [Z]-1[I]
Explanation: The relation between voltage current and admittance matrices is [I] = [Y] [V]. here I represents the current matrix, Y is the admittance matrix and V is the voltage matrix.
7. Admittance and impedance matrices of a micro waves network are related as:
a) [Y] = [Z]-1
b) [Y] = [Z]
c) [V] = [Z] [Z]-1
d) [Z] = [V] [V]-1
Explanation: Both admittance and impedance matrix can be defined for a microwave network. The relation between these admittance and impedance matrix is [Y] = [Z]-1. Admittance matrix is the inverse of the impedance matrix.
8. The element of a Z matrix, Zij can be given in terms of voltage and current of a microwave network as:
a) ZIJ = VI/IJ
b) ZIJ = VIIJ
c) 1//ZIJ = 1/JIVI
d) VIJ = IJ/JI
Explanation: The element Zij of a Z matrix is defined as the ratio of voltage at the ith port to the current at the jth port given that all other currents are set to zero.
9. In a two port network, if current at port 2 is 2A and voltage at port 1 is 4V, then the impedance Z₁₂ is:
a) 2 Ω
b) 8 Ω
c) 0.5 Ω
d) Insufficient data
Explanation: Z12 is defined as the ratio of the voltage at port 1 to the current at port 2. Substituting the given values in the above equation, Z12 parameter of the network is 2 Ω.
10.In a 2 port network, if current at port 2 is 2A and voltage at port 1 is 4 V, then the admittance Y₂₁ is:
a) 0.5 Ʊ
b) 8 Ʊ
c) 2 Ʊ
d) 4 Ʊ
Explanation: Admittance parameter Y12 is defined as the ratio of current at port 1 to the voltage at port 2. Taking the ratio, the admittance Y12 is 0.5 Ʊ.