MCQs on Radio Wave Propagation
Q1: Mathematical prediction of radio waves was done by
a) Einstein
b) Hertz
c) Faraday
d) Maxwell
Answer: (d) Maxwell
Q2: The electric field and magnetic field of a radio wave are
a) Perpendicular to each other
b) Perpendicular to the direction of propagation
c) Both a and b
d) None of the above
Answer: (c) Both a and b
Q3: The speed of radio wave in free space is
a) 3 x 106 metres/second
b) 3 x 108 metres/second
c) 3 x 106 miles/second
d) 3 x 108 miles/second
Answer: (b) 3 x 108 metres/second
Q4: Radio waves would strongly reflect off
a) A flat insulating surface of the right size
b) A flat metallic surface of the right size
c) A flat dielectric surface of the right size
d) A flat body of water
Answer: (b) A flat metallic surface of the right size
Q5: Radio waves sometimes bend around the corners due to
a) Reflection
b) Diffusion
c) Refraction
d) Diffraction
Answer: (d) Diffraction
Q6: Which of the following is the phenomenon caused when Radio waves travel in two or more paths during propagation and produce slowly-changing phase differences between signals?
a) Absorption
b) Fading
c) Baffling
d) skip
Answer: (b) fading
Q7: High-frequency long-distance propagation mostly depends on
a) Ionospheric reflection
b) Tropospheric reflection
c) Ground reflection
d) Inverted reflection
Answer: (a) Ionospheric reflection
Q8: What is the distance from the far end of the ground wave to the nearest point where the sky wave returns to earth called?
a) Angle of radiation
b) maximum usable frequency
c) Skip distance
d) Skip zone
Answer: (d) Skip zone
Q9: Which of the following are electromagnetic
a) Radio waves
b) Light
c) Gamma waves
d) All the above
Answer: (d) All the above
Q10: The radio waves were demonstrated experimentally by
a) Hertz
b) Maxwell
c) Marconi
d) Armstrong
Answer: (a) Hertz
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MCQ on Electric flux
Q2: If a unit positive charge is kept in the air. Then the total flux coming out of unit charge is
a) 4πε0-1
b) 4πε0
c) ε0-1
d )ε0
Answer: (c)ε0-1
Q3: What is the value of electric flux (Φ) on a plane of area 1m2 on which an electric field of 2 V/m crosses with an angle of 300.
a) 1 Vm
b) 2 Vm
c) 3 Vm
d) 4 Vm
Answer: (a) 1 Vm
Q4: Determine the electric flux of a flat square having an area of 10m2 is a uniform electric field of 8000 N/C passing perpendicular to it
a) 8 x 105 Nm2/C
b) 8 x 104 Nm2/C
c) 16 x 105 Nm2/C
d) 4 x 104 Nm2/C
Answer: (b) 8 x 104 Nm2/C
Q5: A plane surface is rotated in a uniform electric field. When is the flux of the electric field through the surface maximum?
a) When the surface is perpendicular to the field
b) When the surface is parallel to the field
c) When the surface is at an angle of 300 with the field
d) When the surface is at an angle of 450 with the field
Answer: (a) When the surface is perpendicular to the field
Q6: When is the flux through a surface taken as positive
a) VWhen the flux lines are directed inwards
b) When the flux lines are directed outwards
c) No flux lines through the surface
d) Flux lines are parallel to each other
Answer: (b) When the flux lines are directed outwards
Q7: The net charge through a closed surface in a given medium depends on
a) Size of the surface
b) Charge of the surface
c) The shape of the surface
d) Area of the surface
Answer: (b) Charge of the surface
Q8: The dimension of electric flux is
a) [M2L2T3A1]
b) [MLT-3A-1]
c) [M3L3T-3A-1]
d) [ML3T -3A-1]
Answer: (d) [ML3T -3A-1]
Q9: The electric flux through a cubical Gaussian surface enclosing net charge q is q/ε0. While the electric flux through one face of a cube is
a) q/ε0
b) q/6ε0
c) q/4πε0
d) q/4ε0
Answer: (b) q/6ε0
Q10: A point charge q is placed at a distance a/2 directly above the centre of the square of side a. The electric flux through the square is
a) q/ε0
b) q/6ε0
c) q/4πε0
d) q/4ε0
Answer: (b) q/6ε0
