Antenna & Wave Propagation Test Questions Set 2

1)   Which among the following exhibits perpendicular nature in TEM wave?

a. Electric field
b. Magnetic field
c. Direction of propagation
d. All of the above
Answer  Explanation  Related Ques

ANSWER: All of the above

Explanation:
No explanation is available for this question!


2)   Which equations are regarded as wave equations in frequency domain for lossless media?

a. Maxwell's
b. Lorentz
c. Helmholtz
d. Poisson's
Answer  Explanation  Related Ques

ANSWER: Helmholtz

Explanation:
No explanation is available for this question!


3)   If the magnetic field component of a plane wave in a lossless dielectric is H = 50 sin (2π x 106 t – 6x) az  mA/m , what will be the wave velocity?

a. 1.047 x 106 m/s
b. 1.257 x 106 m/s
c. 2.50 x 106 m/s
d. 3 x 106 m/s
Answer  Explanation  Related Ques

ANSWER: 1.047 x 106 m/s

Explanation:
No explanation is available for this question!


4)   In an electrical circuit,which nature of impedance causes the current & voltages in phase?

a. Reactive
b. Resistive
c. Capacitive
d. Inductive
Answer  Explanation  Related Ques

ANSWER: Resistive

Explanation:
No explanation is available for this question!


5)   Which type of ground wave travels over the earth surface by acquiring direct path  through air from transmitting to receiving antennas?

a. Surface wave
b. Space wave
c. Both a & b
d. None of the above
Answer  Explanation  Related Ques

ANSWER: Space wave

Explanation:
No explanation is available for this question!


6)   After which phenomenon/phenomena do the waves arrive at the receiving antenna in ionospheric propagation?

a. Reflection or Scattering
b. Refraction
c. Defraction
d. All of the above
Answer  Explanation  Related Ques

ANSWER: Reflection or Scattering

Explanation:
No explanation is available for this question!


7)   By which name/s is an ionospheric propagation, also known as?

a. Sea wave propagation
b. Ground wave propagation
c. Sky wave propagation
d. All of the above
Answer  Explanation  Related Ques

ANSWER: Sky wave propagation

Explanation:
No explanation is available for this question!


8)   According to Snell's law in optics, if a ray travels from dense media to rarer media, what would be its direction w.r.t the normal?

a. Towards
b. Away
c. Across
d. Beside
Answer  Explanation  Related Ques

ANSWER: Away

Explanation:
No explanation is available for this question!


9)   Which mechanism/s is/are likely to occur in mid-frequency operation corresponding to ionospheric region?

a. Only Reflection
b. Only Refraction
c. Partial reflection & refraction
d. None of the above
Answer  Explanation  Related Ques

ANSWER: Partial reflection & refraction

Explanation:
No explanation is available for this question!


10)   Which among the following plays a primary role in generation of conduction current in an ionosphere due to presence of electric field?

a. Ions
b. Motion of electrons
c. Neutral molecules
d. None of the above
Answer  Explanation  Related Ques

ANSWER: Motion of electrons

Explanation:
No explanation is available for this question!


11)   Which type of wire antennas are also known as dipoles?

a. Linear
b. Loop
c. Helical
d. All of the above
Answer  Explanation  Related Ques

ANSWER: Linear

Explanation:
No explanation is available for this question!


12)   Which antennas are renowned as patch antennas especially adopted for space craft applications?

a. Aperture
b. Microstrip
c. Array
d. Lens
Answer  Explanation  Related Ques

ANSWER: Microstrip

Explanation:
No explanation is available for this question!


13)   Which conversion mechanism is performed by parabolic reflector antenna?

a. Plane to spherical wave
b. Spherical to plane wave
c. Both a and b
d. None of the above
Answer  Explanation  Related Ques

ANSWER: Spherical to plane wave

Explanation:
No explanation is available for this question!


14)   Which antenna radiating region/s has/have independent nature of angular field distribution over the distance from the antenna?

a. Reactive near-field region
b. Fresnel region
c. Fraunhofer region
d. All of the above
Answer  Explanation  Related Ques

ANSWER: Fraunhofer region

Explanation:
No explanation is available for this question!


15)   Sterdian is a measurement unit of __________

a. Point angle
b. Linear angle
c. Plane angle
d. Solid angle
Answer  Explanation  Related Ques

ANSWER: Solid angle

Explanation:
No explanation is available for this question!


16)   According to the geometry, how many sterdians are present in a full sphere?

a. π/2
b. π
c.
d.
Answer  Explanation  Related Ques

ANSWER: 4π

Explanation:
No explanation is available for this question!


17)   The vector magnetic potential shows the inverse relationship with its ____

a. Source
b. Distance of point from the source (R)
c. Both a and b
d. None of the above
Answer  Explanation  Related Ques

ANSWER: Distance of point from the source (R)

Explanation:
No explanation is available for this question!


18)   In retarded potentials, what factor of time delay is generally introduced in A & V equations?

a. R + c
b. R - c
c. R/c
d. R x c
Answer  Explanation  Related Ques

ANSWER: R/c

Explanation:
No explanation is available for this question!


19)   In the solutions of inhomogeneous vector potential wave equation, which component exists if the source is at origin and the points are removed from the source (Jz = 0)?

a. Inward
b. Outward
c. Both a and b
d. None of the above
Answer  Explanation  Related Ques

ANSWER: Outward

Explanation:
No explanation is available for this question!


20)   If a half-wave dipole operates at 300 MHz with λ = 0.5m & D0 = 1.643, what will be its effective area?

a. 0.032 m2
b. 0.047 m2
c. 0.65 m2
d. 0.99 m2
Answer  Explanation  Related Ques

ANSWER: 0.032 m2

Explanation:
No explanation is available for this question!


21)   Dipole antenna is symmetrical in nature where the two ends are at equal potentials with respect to _____point

a. Initial
b. Eventual
c. Mid
d. None of the above
Answer  Explanation  Related Ques

ANSWER: Mid

Explanation:
No explanation is available for this question!


22)   Which term is regarded as an inductive field as it is predictable from Biot Savart law & considered to be of prime importance at near field or the distance close to current element?

a. 1/ r
b. 1/ r2
c. 1/ r3
d. 1/ r4
Answer  Explanation  Related Ques

ANSWER: 1/ r2

Explanation:
No explanation is available for this question!


23)   What is the nature of current distribution over the small dipoles?

a. Spherical
b. Rectangular
c. Triangular
d. Square
Answer  Explanation  Related Ques

ANSWER: Triangular

Explanation:
No explanation is available for this question!


24)   For receiving a particular frequency signal, which tuning component must be used by the loop to form a resonant circuit for tuning to that frequency?

a. Capacitor
b. Inductor
c. Resistor
d. Gyrator
Answer  Explanation  Related Ques

ANSWER: Capacitor

Explanation:
No explanation is available for this question!


25)   If the radius of loop is λ/ 20 in a free space medium,what will be the radiation resistance of 8-turn small circular loop?

a. 0.7883 Ω
b. 50.45 Ω
c. 123.17 Ω
d. 190.01 Ω
Answer  Explanation  Related Ques

ANSWER: 123.17 Ω

Explanation:
No explanation is available for this question!


26)   What is the far-field position of an electric short dipole?

a. Along x-axis
b. Along y-axis
c. Along z-axis
d. Along xy plane
Answer  Explanation  Related Ques

ANSWER: Along z-axis

Explanation:
No explanation is available for this question!


27)   What would happen if the rms value of induced emf in loop acquires an angle θ = 90°?

a. Wave is incident in direction of plane of the loop with induced maximum voltage
b. Wave is incident normal to plane of the loop with no induced voltage
c. Wave is incident in opposite direction of plane of the loop with minimum voltage
d. None of the above
Answer  Explanation  Related Ques

ANSWER: Wave is incident normal to plane of the loop with no induced voltage

Explanation:
No explanation is available for this question!


28)   If a linear uniform array consists of 9 isotropic elements separated by λ/4, what would be the directivity of a broadside array in dB?

a. 6.53 dB
b. 7.99 dB
c. 8.55 dB
d. 9.02 dB
Answer  Explanation  Related Ques

ANSWER: 6.53 dB

Explanation:
No explanation is available for this question!


29)   If the elements of a binomial array are separated by λ/4, how many shape patterns are generated with no minor lobes?

a. 2
b. 4
c. 8
d. 16
Answer  Explanation  Related Ques

ANSWER: 8

Explanation:
No explanation is available for this question!


30)   What kind of beamwidth is/are produced by Chebyshev arrays for given side lobe level (SLL)?

a. Widest
b. Narrowest
c. Both a and b
d. None of the above
Answer  Explanation  Related Ques

ANSWER: Narrowest

Explanation:
No explanation is available for this question!


31)   If the length of elements of an array is greater than λ/2, which will be the operating region of an array?

a. Transmission line region
b. Active region
c. Reflective region
d. All of the above
Answer  Explanation  Related Ques

ANSWER: Reflective region

Explanation:
No explanation is available for this question!


32)   Which angle of rhombic antenna represents one half of included angle of two legs of one wire?

a. Apex angle
b. Tilt angle
c. Both a and b
d. None of the above
Answer  Explanation  Related Ques

ANSWER: Tilt angle

Explanation:
No explanation is available for this question!


33)   Which among the following is not a disadvantage of rhombic antenna?

a. Requirement of large space
b. Reduced transmission efficiency
c. Maximum radiated power along main axis
d. Wastage of power in terminating resistor
Answer  Explanation  Related Ques

ANSWER: Maximum radiated power along main axis

Explanation:
No explanation is available for this question!


34)   Why are beverage antennas not used as transmitting antenna?

a. Low radiation resistance
b. Low radiation efficiency
c. Both a and b
d. None of the above
Answer  Explanation  Related Ques

ANSWER: Both a and b

Explanation:
No explanation is available for this question!


35)   Which kind of polarization is provided by helical antennas?

a. Plane
b. Elliptical
c. Circular
d. All of the above
Answer  Explanation  Related Ques

ANSWER: Circular

Explanation:
No explanation is available for this question!