Elements of Remote Sensing MCQ Questions and Answers in Civil Engineering

Question. Pick up the correct statement from the following:
(a) For the same feature, the photograph taken from the satellite vertically above the aircraft, the height displacement is lesser than the aerial photograph
(b) The scale of the aerial photograph depends upon the scale of the topography
(c) The feature at the principal point has no height displacement
(d) All of the above

Answer : D

Question. Pick up the correct statement from the following:
(a) Phase of a wave is expressed as a fraction of a period with respect to a reference
(b) Phase is usually specified by angular measure with one period being 360°
(c) The reference for finding the phase of a wave is taken from the previous passage through zero from the negative to the positive direction
(d) All of these

Answer : D

Question. Crop Acreage and Production Estimation (CAPE) was funded and taken up in 1983 by:
(a) USA
(b) European Union
(c) Russia
(d) India

Answer : D

Question. 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

Answer : B

Question. Which one of the following statements is correct regarding the GPS satellites?
(a) The nominal altitude is about 20,200 km
(b) The inclination of axis satellite is 55°
(c) The satellite transmits two L band signals (L1 with 1575.42 MHz and L₂ with 1276.6 MHz)
(d) All of these

Answer : D

Question. The infrared portion of EMR lies between
(a) 0.4 - 0.7 μm
(b) 0.5 mm to 1 μm
(c) 0.7 - 1.3 μm
(d) 0.7 to 14 μm

Answer : D

Question. Pick up the correct definition from the following with response to GIS.
(a) Common boundary between two areas of a locality is known as adjacency
(b) The area features which are wholly contained within another area feature, is known so containment
(c) The geometric property which describes the linkage between line features is defined as connectivity
(d) All of these

Answer : D

Question. The most widely used antenna in GPS is
(a) Parabolic antenna
(b) Microstrip antenna
(c) Horn antenna
(d) Slotted antenna

Answer : B

Question. The remote sensing techniques applied for the earth's surface features, is generally confined to the following wave lengths:
(a) 0.4 to 1.3, 1.5 to 1.8, 2.2 to 2.6 μm
(b) 2.2 to 2.6, 3.0 to 3.6, 4.2 to 5.0 μm
(c) 4.2 to 5.0, 7.0 to 15.0 μm and 1 cm to 30 cm
(d) All of these

Answer : D

Question. Which one of the following statements is correct?
(a) Snow albedo falls at all wave length with the increase of grain size
(b) The effect of grain size on reflection is maximum in the near-IR region
(c) The effect of grain size on reflection is low in the visible region of the spectrum
(d) All of these

Answer : D

Question. The various stages occuring in GPS system are described below:
1. Generation of an output to the user
2. Detection of the GPS signals
3. Processing the data in the built-in-computer
4. Decoding the GPS signal.
The correct sequence of the stages is:
(a) 1, 2, 3, 4
(b) 2, 3, 4, 1
(c) 2, 4, 3, 1
(d) 3, 1, 2, 4

Answer : C

Question. Pick up the correct statement from the following:
(a) Frequency is the number of wave crests passing a fixed point in one second
(b) Frequency of a wave is measured in Hertz (Hz)
(c) Amplitude of a wave is the height of its crust from the mid-point
(d) All of these

Answer : D

Question. Pick up the correct statement from the following:
(a) The first man-made satellite, 'Sputnik-l' was launched on 4th October 1957
(b) The United State's Explorer 6 transmitted the first picture of the earth in August 1959
(c) Television Infrared Observation Satellite (TIROS) designed for meteorological observations, started systematic earth observations from space from 1st April 1960
(d) All of these

Answer : D

Question. Which one of the following geometric errors of satellite sensors is random?
(a) Scan skew
(b) Panoramic distortion
(c) Earth rotation
(d) Altitude variation

Answer : D

Question. The ratio of the total solar radiant energy returned by a planetary body to the total radiant energy incident on the body, the called:
(a) Reflectance
(b) Reflectance factor
(c) Albedo
(d) None of these

Answer : C

Question. Remote sensing techniques make use of the properties of ___________ emitted, reflected or diffracted by the sensed objects:
(a) Electric waves
(b) Sound waves
(c) Electromagnetic waves
(d) Wind waves

Answer : C

Question. If θ is the angle of scan measured from the nadir, the ground distance swept by the sensor IFOV is proportional to:
(a) sin²θ
(b) cos²θ
(c) sec²θ
(d) tan²θ

Answer : C

Question. The changes in the reflectivity/emissivity with time, is called:
(a) Spectral variation
(b) Spatial variation
(c) Temporal variation
(d) None of these

Answer : C

Question. Which one of the following statement is incorrect regarding the electromagnetic radiation?
(a) These are produced by the motion of electric charge
(b) The oscillation of charged particles sets up changing electric fields
(c) The changing electric fields induce the changing magnetic fields in the surrounding medium
(d) None of these

Answer : D

Question. Which one of the following statements is correct?
(a) During the day, earth reflects solar radiation
(b) During the day, earth reflects both solar radiations the emission from its surface
(c) During the night, earth emits radiation from its surface
(d) All of these

Answer : D

Question. Which one of the following statements regarding remote sensing is correct?
(a) The interaction of the electromagnetic radiation with the target
(b) The emission of electromagnetic radiation from the target
(c) Both (A) and (B)
(d) Neither (A) nor (B)

Answer : C

Question. Pick up the correct statement from the following:
(a) A graphical representation of spectral reflectance verses the various growth stages of a crop, depicts a phonologic pattern
(b) The changes in the polarization of the radiation reflected or emitted by an object, is known as polarization variation
(c) The degree of polarization is a characteristic of the object which helps in the identification of the object
(d) All of these

Answer : D

Question. Pick up the correct statement from the following:
(a) In remote sensing technique, the observation place, is called a platform
(b) Platforms may be either stationary or mobile
(c) Spatial resolution of the imaging system becomes poorer with increase of platform height
(d) All of these

Answer : D

Question. 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

Answer : D

Question. If flying height of a spacecraft is H, the length of air base is B and the parallax difference between two points is dp, then the difference in height
(a) h = dp/BH
(b) h = B/H × dp
(c) h = dp/HB
(d) h = BHbp

Answer : A

Question. 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

Answer : B

Question. The value of energy quantum for radiation of any frequency is proportional to:
(a) The frequency
(b) The reciprocal of the energy
(c) The square of the frequency
(d) The square root of the frequency

Answer : A

Question. Which one of the following relationship between the wave length (λ) and frequency and the speed (C) of the electromagnetic wave is correct?
(a) C = v + λ
(b) C = λ/v
(c) C = vλ
(d) C = 1/vλ

Answer : C

Question. 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

Answer : B

Question. Which one of the following statements is correct?
(a) The function of an information system is to improve one’s ability to make decisions
(b) The information system is the chain of operations
(c) A map is a collection of stored, analyzed data, its stored information is suitability used in making decisions
(d) All the above

Answer : D

Question. The object of photo-interpretation is:
(a) Identification
(b) Recognition of objects
(c) Judging the significance of objects
(d) All of these

Answer : D

Question. Pick up the correct statement from the following:
(a) Indian space effort started in 1962 with the establishment of a rocket
(b) Development of space (DOS) was established by the Government of India in 1972
(c) Indian Space Research Organization (ISRO) is responsible for the space technology and its application to various activities
(d) All of these

Answer : D

Question. "An Electromagnetic wave falls on to a boundary between two losses 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:
(a) Fresnel reflection
(b) Fresnel refraction
(c) Snell's law
(d) None of these

Answer : A

Question. The altitudinal distance of a geostationary satellite from the earth is about:
(a) 26,000 km
(b) 30,000 km
(c) 36,000 km
(d) 44,000 km

Answer : C

Question. Sensor IFOV is proportional to:
(a) sin²
(b) cos²
(c) sec²
(d) tan²

Answer : C

Question. According to the Snell's law if an electromagnetic wave is incident in a medium (refractive index n₁) on another medium (refractive index n₂);
(a) The angle of incidence is equal to the angle of refraction
(b) The angle of refraction (θr) is given by sin θ₂ = n₁/n₂ sin θ_i
(c) Both (A) and (B)
(d) Neither (A) nor (B)

Answer : B

Question. The arrangement of terrain features which provides attributes: the shape, size and texture of objects, is called:
(a) Spectral variation
(b) Spatial variation
(c) Temporal variation
(d) None of these

Answer : B

Question. The code based GPS receivers are generally used for:
(a) Vehicle tracking
(b) Land navigation
(c) Trans movement
(d) All of these

Answer : D

Question. Pick up the correct statement from the following:
(a) Permeability is a measure of conducting the magnetic lines of force in the material
(b) Permeability is a measure of the extent to which magnetic lines of force can penetrate a medium
(c) Permeability is expressed as the ratio of the magnetic flux density (B) to the field strength of the magnetizing field
(d) All of these

Answer : D

Question. 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

Answer : B

Question. Which one of the following parameters is accurate for DGPS?
(a) Positional accuracies ~ 1 - 2 m if rover is less than 1-2 km from the reference station
(b) Positional accuracies ~ 2 - 5 m if rover is less than 2-5 km from the reference station
(c) Positional accuracies ~ 5 - 10 m if rover is less than 5-10 km from reference station
(d) Positional accuracies ~ 5 - 10 m if rover is less than 25 km

Answer : A

Question. The optical property of a water body depends on:
(a) Absorption by the dissolved material
(b) Absorption by the suspended particulate matter
(c) Scattering by the suspended particulate matter
(d) All of these

Answer : D

Question. Which one of the following frequency regions is a part of sun's radiation?
(a) Ultraviolet frequency region
(b) Infrared frequency region
(c) Radio frequency region
(d) All of these

Answer : D

Question. Spatial variation in horizontal and vertical directions is caused due to:
(a) Physical weathering of rocks
(b) Chemical weathering of rocks
(c) Biological weathering of rocks
(d) All of these

Answer : D

Question. Leaf reflectance depends primarily on:
(a) The pigments
(b) Internal cell structure
(c) Equivalent water content
(d) All of these

Answer : D

Question. Pick up the correct statement from the following:
(a) Phytoplankton contains photosynthetically active pigment
(b) An increase of phytoplankton increases the back scattering in the green region
(c) An increase of phytoplankton absorbs the bule region rapidly
(d) An increase of phytoplankton decreases the back scattering in the green region

Answer : D

Question. 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

Answer : D

Question. While propagating through homogeneous, isotropic media,
(a) Directions of both the fields are orthogonal
(b) Both the fields are at right angles to the direction of propagation
(c) Both (A) and (B)
(d) Neither (A) nor (B)

Answer : C

Question. Due to perturbation of the orbit, satellite orbit parameters are frequently updated on measurements carried out by its
(a) Six ground stations
(b) Five ground stations
(c) Four ground stations
(d) Three ground stations

Answer : B

Question. Orbital radius of GPS satellites is approximately:
(a) 15,200 km
(b) 26,600 km
(c) 18,400 km
(d) 36,000 km

Answer : B

Question. Which one of the following statements is correct?
(a) π radians equal to 180°
(b) The cone subtended by an area on the sphere at the centre, is called the solid angle
(c) The solid angle is equal to the ratio of the area on the sphere and the square of the radius of the sphere
(d) All of these

Answer : D

Question. Pick up the important characteristic of a target which facilitates its identification from the following:
(a) Spectral variation
(b) Spatial variation
(c) Temporal variation
(d) All of these

Answer : D

Question. Geodimeter is based on:
(a) Propagation of modulated light waves
(b) Propagation of infrared radiation
(c) The visible light as carrier with frequency of the order of 5 × 1014 Hz
(d) High frequency radio waves

Answer : A

Question. Which one of the following factors does not affect the scale of the air photographs?
(a) Focal length
(b) Flying height
(c) Ground elevation
(d) None of these

Answer : D

Question. Who coined the term, ‘Remote sensing’.
(a) Evelyn L. Pruitt, a geographer
(b) Gaspard Felix Tournachon, a French scientist
(c) Wilbur Wright, an Italian scientist
(d) None of these

Answer : A

Question. ‘A’ and ‘B’ are two towers of equal height diametrically opposite on either side of the nadir point, at 3 km and 5 km distances. Which one of the following statements is correct?
(a) Height displacement of A will be less than that of B
(b) Height displacement of B will be less than that of A
(c) Height displacement of A and B is equal
(d) Height displacement of A and B will be towards each other

Answer : A

Question. Which one of the following statement is correct?
(a) Radiant energy expressed in Joules, is the energy associated with electromagnetic radiation
(b) The rate of transfer of radiant energy is called flux and is expressed in watts
(c) The radiant energy which falls upon a surface is termed as irradiance
(d) All of these

Answer : D

Question. 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

Answer : D

Question. The refractive index of the ocean water:
(a) Increases with salinity
(b) Increases with temperature
(c) Decreases with salinity
(d) Decreases with temperature

Answer : A

Question. Which one of the following quantities forms the basis of radiometry?
(a) Radiant energy (Q)
(b) Radiant flux (φ)
(c) Radiant intensity (I)
(d) All of these

Answer : D

Question. In GPS, receivers are used are;
(a) Electronic clocks
(b) Atomic clocks
(c) Quartz clocks
(d) Mechanical clocks

Answer : C

Question. The part radiation due to scattered/diffused radiation entering the field of view of a remote sensor other than that from the required target,
(a) Reduces the contrast of the image and also its sharpness
(b) Increases the contrast of the image but reduces the sharpness
(c) Increases both the contrast and sharpness
(d) Reduces the contrast but increases the sharpness

Answer : A

Question. Which one of the following helps to identify the objects on the earth surface?
(a) Atmospheric window
(b) Signature
(c) Radiometric error
(d) None of these

Answer : B

Question. Which one of the following errors is produced by platform characteristics of the sensor?
(a) Altitude variation
(b) Altitude
(c) Orbit drift
(d) All of these

Answer : D

Question. Which one of the following parameters is considered to determine the reflectance of a vegetation canopy?
(a) Solar zenith angle
(b) Azimuth angle
(c) Look angle
(d) All of these

Answer : D

Question. The normal altitude of GPS satellite is about
(a) 16,200 km
(b) 20,200 km
(c) 24,400 km
(d) 36,100 km

Answer : B