Elements of Remote Sensing MCQs

Question 1

Pick up the correct statement from the following :

Accepted Answer

All of these

Answer

Electromagnetic wave is composed of electric and magnetic fields

Answer

Electric and magnetic fields of electromagnetic wave remain mutually orthogonal and transverse to the direction of propagation.

Answer

If the electromagnetic wave moves in the z-direction, its electric vector remains in the XY plane along-any direction.

Question 2

Pick up the correct statement from the following :

Accepted Answer

All of these

Answer

Phase of a wave is expressed as a fraction of a period with respect to a refrence

Answer

Phase is usually specified by angular measure with one period being 360?

Answer

Superposition of the coherent waves produce interference

Question 3

For perfect coherent radiation, which one of the following statement is correct ?

Accepted Answer

All of these

Answer

Both the waves must have single frequencies

Answer

The directions of motion of both waves are parallel.

Answer

The waves must be collimated

Question 4

Pick up the correct statement from to following :

Accepted Answer

All of these ,

Answer

For complete temporal coherence, the waves must be mono chromatic.

Answer

For spatial coherence, the phase difference between two points in space is constant with time.

Answer

The reference for finding the phase of a wave is taken from the previous passage through zero from the negative to the positive direction.

Question 5

An Electromagnetic wave falls on to a boundary between two loss less homogeneous media with different refractive indices, a part of the wave is reflected back to the incident medium and the rest is transmitted on to the second media. This phenomenon is known as

Accepted Answer

Fresnel reflection

Answer

Fresnel refraction

Answer

Snell's law

Answer

None of these

Question 6

According to the Snell's law if an electromagnetic wave is incident in a medium (refractive index ni.) on an other medium (refractive index n2) ;

Accepted Answer

the angle of refraction (Or) is given by sin 02 =? sin Oi n2

Answer

the angle of incidence is equal to the angle of refraction

Answer

Both (a) and (b)

Answer

neither (a) nor (b)

Question 7

Critical angle of electromagnetic radiation takes place if

Accepted Answer

angle of refraction is equal to 90?

Answer

. angle of incidence is equal to angle of refraction

Answer

angle of incidence is greater than the angle of refraction

Answer

angle of incidence is equal to 900

Question 8

Pick up the correct statement from the following:

Accepted Answer

All the these

Answer

The refractive index of a medium varies according to the wavelength of the radiation,

Answer

The variation of the refractive index with wave length, is called dispersion,

Answer

The splitting of colours of white light by passing through a prism, is caused due to dispersion.

Question 9

The energy transported by the electromagnetic wave is proportional to :

Accepted Answer

the square of the altitude of the wave

Answer

the altitude of the wave

Answer

the cube of the altitude of the wave

Answer

the square roof of the amplitude