Coherence of two electromagnetic waves takes place if their phase difference is_________________?

Related Mcqs:

1. The coherence length over which there is a strong relationship between amplitudes is_________________?

   A. Directly proportional to the bandwidth
   B. Inversely proportional to the bandwidth
   C. The square of the bandwidth
   D. None of these

2. For C band Synthetic Aperture Radar (SAR) with Doppler band width of 1300 Hz, the coherence length loch is_____________?

   A. 130 km
   B. 230 km
   C. 250 km
   D. 500 km

3. Critical angle of electromagnetic radiation takes place if__________________?

   A. Angle of incidence is equal to angle of refraction
   B. Angle of incidence is greater than the angle of refraction
   C. Angle of incidence is equal to 90°
   D. Angle of refraction is equal to 90°

4. In case of reflection and refraction of electromagnetic radiation ?

   A. Angle of incidence = angle of refraction
   B. Angle of incidence = angle of reflection
   C. Angle of refraction = sum of the angles of incidence and refraction
   D. All the above

5. Electromagnetic spectrum contains________________?

   A. Gamma rays (wave length < 10-10 m)
   B. Ultraviolet rays (wave length < 10-6 m)
   C. Infrared rays (wave length < 10 -4 m)
   D. All of these

6. According to the Snell’s law if an electromagnetic wave is incident in a medium (refractive index n1) on another medium (refractive index m2)________________?

   A. The angle of incidence is equal to the angle of refraction
   B. The angle of refraction r) is given by sin i
   C. Both A. and B.
   D. Neither A. nor B.

7. Electromagnetic radiation_______________?

   A. Produces a time varying magnetic field and vice versa
   B. Once generated, remains self-propagating
   C. Is capable to travel across space
   D. All of these

8. The instruments which provide electromagnetic radiation of specified wave length or a band of wave lengths to illuminate the earth surface are called________________?

   A. Sensors
   B. Passive sensors
   C. Active sensors
   D. None of these

9. The spectral region of the electromagnetic radiation which passes through the atmosphere without much attenuation is known as__________________?

   A. Ozone hole

   B. Atmospheric window

   C. Ozone window

   D. Black hole

10. The interaction of the electromagnetic radiation produced with a specific wave length to illuminate a target on the terrain for studying its scattered radiance, is called____________________?

    A. Passive remote sensing
    B. Active remote sensing
    C. Neutral remote sensing
    D. None of these