EC 8701 Antennas and Microwave Engineering IAT 1

1. What is the wavelength of Super high frequency (SHF) especially used in Radar & satellite communication?

• 1 m – 10 cm

• 1 cm – 10 cm

• 10 cm – 1 m

• 0.1 cm – 1 cm

Which among the following is an application of high frequency?

• SONAR

• Subsurface communication

• Radio navigation

• Facsimile

Under which conditions of charge does the radiation occur through wire antenna?

• For a charge with no motion

• For a charge moving with uniform velocity with straight & infinite wire

• For a charge oscillating in time motion

• All of the above

In a non-isotropic directional antenna, which radiating lobe axis makes an angle of 180° w.r.t. major beam of an antenna?

• Minor lobe

• Side lobe

• Side lobe

• None of the above

At which angles does the front to back ratio specify an antenna gain?

• 0° & 180°

• 90° & 180°

• 180° & 270°

• 180° & 360°

Which among the following defines the angular distance between two points on each side of major lobe especially when the radiation drops to zero?

• Half power beam width (HPBW)

• First null beam width (FNBW)

• Side lobe level (SLL)

• Front to back ratio (FBR)

If an observation point is closely located to the source, then the field is termed as

• Induced

• Radiated

• Reflected

• Far-field

Which waveform plays a crucial role in determining the radiation pattern of the dipole/wire antennas?

• Current

• Voltage

• Frequency

• Phase

How are the infinitesimal dipoles represented in terms of antenna length and signal wavelength?

• l ≤ (λ /50)

• (λ/50 ) < l ≤ (λ /10)

• l = λ/2

• None of the above

Which pattern is generated due to plotting of square of amplitude of an electric field?

• Field Pattern

• Voltage Pattern

• Power Pattern

• All of the above