64. The energy transported by the electromagnetic wave is proportional to :

A. the altitude of the wave

B. the square of the altitude of the wave

C. the cube of the altitude of the wave

D. the square roof of the amplitude

65. Which one of the following relationship between the wave length (X), and frequency and the speed (C) of the electromagnetic wave is correct ?

A. C = v + X

B. C=v-X

C. C = v X

D. C = v 1

66. 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

67. For C band Synthetic Aperture Radar (SAR) with Doppler band width of 1300 Hz, the coherence length lcoh is:

A. 130 km

B. 230 km

C. 250 km

D. 500 km

68. Pick up the correct statement from the following

A. The minimum frequency of light for which no electrons are emitted, is called threshold frequency.

B. Polarising angle of glass is,57?.5,

C. At the polarising angle, the reflected and refracted rays are orthogonal

D. All the above

69. Polarising angle (i) and refractive index (g) of the reflecting surface are related by:

A. sin i =

B. cos i =

C. tan i = p,

D. tan i =

70. A perfectly black body :

A. is a diffuse emitter

B. absorbs all the radiations of every wave lengths

C. emits power of every wave length

D. All the above

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