## Elements of Remote Sensing MCQ Practice Questions (Civil) Set 1

##### GPS has been widely recognized as accurate, fast and cost-effective method for the following:

Options are :

• Collection of the geographic coordinate data used in GIS
• All of these
• For determination of precise orbit and altitude of low earth orbiting satellites

##### Pick up the correct statement from to following:

Options are :

• All of these
• Superposition of the coherent waves produce interference
• For complete temporal coherence, the waves must be mono chromatic
• With 0 phase difference, the constructive interference takes place
• For spatial coherence, the phase difference between two points in space is constant with time

##### The semi-infinite snow albedo is proportional to the square root of the grain radius:

Options are :

• In the 0.2 to 0.4 ?m wave length region
• In the 0.8 to 1.2 ?m wave length
• None of these
• In the 0.4 to 0.8 ?m wave length region

Answer :In the 0.4 to 0.8 ?m wave length region

Options are :

• Yellow
• Green
• Red
• Deep blue

##### Remote sensing techniques are being usefully employed for the purpose of:

Options are :

• Protection of the environment
• Land use
• Improving natural resource management
• All of these

##### Pick up the correct statement from the following:

Options are :

• Water molecules and salt-ions in the ocean scatter the lower wave length more
• An increase in the back scattering coefficient with shorter wave length gives a deep blue colour for clear oceanic water
• All of these
• The ratio of the upwelling irradiance just below the surface and downwelling irradiance just above the surface is called reflectance ratio

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

Options are :

• The directions of motion of both waves are parallel
• Both the waves must have single frequencies
• All of these
• The waves must be collimated

##### "All bodies at temperatures above absolute zero degree emit electromagnetic radiation at different wave length", is known as:

Options are :

• Planktan's law
• Lambert's cosine law
• None of these
• Plank's law

##### The maximum absorption of solar radiation due to ozone occurs at wave lengths:

Options are :

• Shorter than 0.3 ?m
• Greater than 0.3 ?m
• None of these
• Shorter than 0.2 ?m

Options are :

• Yellow
• Blue
• Green
• Red

##### In which part of the reflective optical infrared region, the effect of multiple leaves in vegetation canopy is maximum ?

Options are :

• In all the above region
• The short wave IR (1.3 - 2.7 ?m) region
• The visible (0.4 - 0.7 ?m) region
• The near-IR (0.7 - 1.3 ?m) region

Answer :The near-IR (0.7 - 1.3 ?m) region

##### Phytoplanktons:

Options are :

• Are microscopic plants
• All of these
• Convert solar energy, dissolved carbon and nitrogen into organic biomass
• Are the first link in all the aquatic and marine food chains

##### Which one of the following statements is correct ?

Options are :

• Higher the dielectric constant of a medium, the poorer is its electric conductivity
• All of these
• Dielectric constant is a pure number and has no dimensions
• The dielectric constant of pure water is 80
• The ratio of the permitivity of a medium and the free space, is called relative permitivity

##### Pick up the incorrect statement regarding the optical infrared region of the electromagnetic spectrum from the following :

Options are :

• Microwave infrared region, 3.0 ? m - 8.0 ?m
• Short wave infrared region, 0.7 ? m - 1.5 ?m
• Near infrared region, 1.5 ? m - 3.0 ?m
• Visible region, 0.4 ?m - 0.7 ?m

Answer :Short wave infrared region, 0.7 ? m - 1.5 ?m

##### Pick up the correct statement from the following:

Options are :

• All of these
• The wave length of gamma rays is 10^(-10) m
• The visible length occupies a small portion of the electromagntic spectrum extending roughly from 0.4 ? m to 0.7?m wave length
• The wave length of radio rays is 10^(6) m

Options are :

• 2, 1, 3, 4
• 3, 2, 1, 4
• 1, 3, 4, 2
• 4, 1, 2, 3

##### Electromagnetic waves are characterised by:

Options are :

• Direction of travel and plane of polarisation
• All of these
• Frequency
• Intensity
• Wave length

##### Pick up the correct statement from the following:

Options are :

• Electromagnetic wave is composed of electric and magnetic fields
• If the electromagnetic wave moves in the z-direction, its electric vector remains in the XY plane along any direction
• Polarization defines the orientation of the fields
• Electric and magnetic fields of electromagnetic wave remain mutually orthogonal and transverse to the direction of propagation
• All of these

##### Which one of the following statements is correct to remote sensing ?

Options are :

• The surface from which emergent radiance is constant in all directions is called Lambertian surface
• All of these
• The ratio of the reflected flux to incident flux is called reflectance which varies fron 0 to 1
• The basic property used to identify objects, is called signature

##### For accurate position fix, the three satellites:

Options are :

• Must be such that one satellite is overhead of the receiver and other two widely separated
• Must be along a common arc
• Must be in vertical line above the receiver
• Must be widely separated and well distributed

Answer :Must be widely separated and well distributed

##### Which one of the following frequencies is a GPS ?

Options are :

• L1 with frequency 1520 MHz
• L1 with frequency 1227.6 MHz
• L1 with frequency 1280.43 Hz
• L1 with frequency 1575.42 MHz

Answer :L1 with frequency 1575.42 MHz

##### Fresh and pure snow reflectance:

Options are :

• Is very high in visible region
• All of these
• Falls off steeply in the near-IR region
• Remains low for longer wave lengths

##### The emission of electrons from a metal plate exposed to light depends on the:

Options are :

• None of these
• Intensity of the light
• Frequency of light

Answer :Intensity of the light Frequency of light

Options are :

• Brown
• Green
• Blue
• Red

##### The range measurements in GPS are made with:

Options are :

• 2 L - band frequencies
• 2 C - band frequencies
• 3 L - band frequencies
• 3 C - band frequencies

Answer :2 L - band frequencies

##### Pick up the correct statement from the following:

Options are :

• The first aerial photography from an aerocraft was made by Willeur Wright in 1909 in Italy
• All of these
• Balloons were used as stable platform for aerial photography in 1903
• Photography was developed in 1826

##### The leaf area index (LAI) is:

Options are :

• None of these
• Two sided leaf area per -unit area of the ground
• One sided leaf area per unit area of the ground
• The average of the two sided area per unit area of the ground

Answer :One sided leaf area per unit area of the ground

##### Which one of the following statements is correct ?

Options are :

• The PN code determines the time taken by the receiver to reach the receiver which is converted into distance
• All of these
• The two L band signals are modulated by the Pseudorandom binary codes (PN)
• Each satellite of the GPS system transmits two L band signals

##### Which one of the following statements is not correct ?

Options are :

• GIS technology is the same as traditional mapping
• GIS technology contains analytic capabilities for overlaying maps
• GIS technology is a tool box for processing maps and fundamental concepts for spatial measurement
• GIS technology is capable to study the environmental surrondings

##### Snow consists of:

Options are :

• Rimed snow crystals
• Snow flakes
• All of these
• Snow crystals