Accidental errors
Do not follow any definite mathematical law
Cannot be removed by applying corrections to the observed values
Are generally small
All the above
Correct Answer :
D. All the above
Related Questions
When a star is between the pole and the horizon, the relationship between latitude (λ), zenith distance (z) and declination δ, is
θ = z + δ
θ = δ - z
θ = 180° - (z + δ)
θ = (z + δ) - 180°
Pick up the correct statement from the following:
If the applied tension to the tape is more than the standard, the tension correction is positive
If the applied tension to the tape is less than the standard, the tension correction is negative
If the temperature during measurement is greater than the standard temperature, the temperature correction is positive
All the above
The declination and right ascension of the sun becomes 23° 27' N and 90° respectively on
March 21
June 21
September 21
December 22
The scale of a tilted photograph of focal length f, taken from an altitude H, along the plate parallel through plumb point, is
f/H sec θ
f sec θ/H
f/H
f/H cos ½θ
Polaris is usually observed for the determination of the latitude when it is
At culmination
At elongation
Neither at culmination nor at elongation
Either at culmination or at elongation
In a tropical year, the numbers of sidereal days are
One less than mean solar days
One more than mean solar days
Equal to mean solar days
None of these
If v, t and f/H are the ground speed of the aircraft, the shutter speed of the camera and the scale of the photograph respectively, then the amount of image displacement
i = v. t. H/f
i = v. f/t. H
i = v. t. (f/H)
i = t. H/v. f
The altitudes of a circumpolar star at culminations are 70° and 10°, both culminations being north of zenith. The declination of the star, is
80°
70°
60°
50°
The latitude (λ) of a place and the altitude (α) of the pole are related by
λ = α
λ = 90° - α
λ = α - 90°
λ = 180° - α
Equation of time which is the difference between apparent solar time and mean solar time at any instant, vanishes during one year
Once
Twice
Thrice
Four times
The normal longitudinal overlap is generally kept
50 %
60 %
70 %
75 %
The angle between the plane of the equator and the plane of the ecliptic, is known as obliquity of the ecliptic and its value is
22° 30'
23° 27'
23° 30'
24° 0'
The elevation of the star at elongation is obtained by
sin α = sin φ cosec δ
sin α = sin φ sec δ
sin α = cos φ sec δ
sin α = cos φ cosec δ
The scale of a tilted photograph of focal length f taken from an altitude H, along the plate parallel through principal point is
f/H sec θ
f sec θ/H
f/H
f/H cos ½θ
The great circle along which the sun appears to trace on the celestial sphere with earth as centre during the year, is called
Equator
Celestial equator
Ecliptic
None of these
The longitudes of two places at latitude 60° N are 93° E and 97° W. Their departure is
5100 nautical miles
5700 nautical miles
120 nautical miles
500 nautical miles
If S is the sum of three angles of a spherical triangle, the spherical excess equals
S - 90°
S - 180°
S - 270°
S - 360°
An aerial photograph may be assumed as
Parallel projection
Orthogonal projection
Central projection
None of these
The average eye base is assumed as
58 mm
60 mm
62 mm
64 mm
The nautical mile is the length of
1 minute of latitude
1 minute of longitude
1 degree of latitude
1 degree of longitude
If δ is the declination of the star and φ is the latitude of the observer, then the azimuth of the star at elongation is given by
sin z = sec φ . cos δ
cos z = sec φ . cos δ
tan z = sec φ . cos δ
None of these
Pick up the correct statement from the following:
The plane passing through the perspective centre of a stereo pair and a ground point, is known as basal plane
Each pair of image points on stereo pair have their own basal plane
Relative orientation means reconstructing the basal plane
All the above
At upper culmination, the pole star moves
Eastward
Westward
Northward
Southward
The correction applied to the measured base of length L is
Tension = (P - Ps)L/AE
Sag = L3w²/24P² where w is the weight of tape/m
Slope = (h²/2L) + (h4/8L3) where h is height difference of end supports
All the above
At lower culmination, the pole star moves
Eastward
Westward
Northward
Southward
If δ is the declination of the star and φ is the latitude of the observer then the hour angle of the star at elongation is given by
sin H = tan φ . cot δ
cos H = tan φ . cot δ
tan H = tan φ . cot δ
None of these
Pick up the incorrect statement from the following. High oblique photographs
May have tilt up to 30°
May include the image of the horizon
May not include the image of the horizon
None of these
Stellar astronomy deals with
Plane surveying
Geodetic surveying
Star observations
Planet observations
In a spherical triangle ABC right angled at C, sin b equals to
sin c sin B
cos c cos B
tan c tan B
sin c cos B
Polaris is usually observed for the determination of the azimuth when it is
At culmination
At elongation
Neither at culmination nor at elongation
Either at culmination or at elongation