The displacement of the pictured position of a point of h elevation on a vertical photograph taken with a camera of 30 cm focal length, from an altitude of 3000 m, is
4.4 mm
5.5 mm
6.5 mm
7.5 mm
Correct Answer :
D. 7.5 mm
Related Questions
The Polaris describes a small circle round the pole whose radius is approximately
1°
2°
3°
4°
Latitude of a place is the angular distance from
Greenwich to the place
Equator to the poles
Equator to the nearer pole
None of these
The method of surveying by triangulation was first introduced by the Dutchman Snell in
1600
1615
1630
1650
The difference of parallax for a given difference in elevation is independent of
Focal length of the camera
Overall size of the photo graphs
Percentage of overlap
All the above
The slotted template method
Is prepared, by graphical method
Is suitable for large areas with less control
Is rapid and accurate
All the above
The station pointer is generally used in
Triangulation surveying
Astronomical surveying
Hydrographical surveying
Photogrammetric surveying
α and β are the angles subtended by a point of elevation h at their air station with respective plumb points. Photo scale and focal length of the lens being S and f respectively. Parallax displacement of the point due to relief, is
h tan α/S
h tan β/S
h (tan α + tan β)/S
h (tan α - tan β)/S
The altitude of a circumpolar star is maximum when it is
At east elongation
At upper culmination
At west elongation
At lower culmination
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
The point at which sun's declination changes from north to south, is known as
First point of Aeries
First point of Libra
Vernal Equinox
Both (b) and (d) of the above
The maximum error in radial line assumption, is
h/H f tan θ
h/H f² tan θ
h/H f² sin θ
h/H f cos θ
The station where observations are not made, but the angles at the station are used in triangulation series, is known as
Satellite station
Subsidiary station
Pivot station
Main station
If two points differing by 1° of latitude and of the same longitude is 110 km apart on the earth, then two astronomical positions on the moon is about
10 km
25 km
30 km
50 km
The principal plane contains
Nadir point
Iso centre
Principal point
All the above
The length of a parallel of λ latitude between two meridians is equal to difference in longitudes multiplied by
sin λ
cos λ
tan λ
cot λ
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
Pick up the correct statement from the following:
Aerial photographs may be either vertical or oblique
Vertical photographs are taken with the axis of camera pointing vertically downward
Vertical photographs are used for most accurate maps
All the above
The want of correspondence in stereo-photographs
Is a good property
Is a function of tilt
Is not affected by the change of flying height between photographs
Is minimum when θ is 3°
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°
Homologous points are
Opposite corners of a photograph
Nodal points of the camera lens
Corresponding points on the ground and photograph
Plumb points of stereo pair of photographs
The latitude of a place was obtained by subtracting the zenith distance of a star from its declination, the observed star was between
Horizon and equator
Equator and zenith
Zenith and pole
Pole and horizon
Pick up the correct statement for horizontal photographs.
Parallel lines do not appear parallel in central projection
The two sides of a road meet at the vanishing point
The lines parallel to the negative plane are projected as parallel lines
All the above
Pick up the correct statement from the following:
The sun's right ascension increases for 0 h to 24 h when it returns to the First point of Aries
The maximum declination of the sun increases up to 23 ½° N on about 21st June
The minimum declination of the sun is zero' on 22nd September
All the above
Perspective centre relates to
Parallel projection
Orthogonal projection
Central projection
None of these
Homologous point is
Photo principal point
Ground principal point
Ground isocenter
All the above
A nautical mile is
One minute arc of the great circle passing through two points
One minute arc of the longitude
1855.109 m
All the above
The rate of change of parallax dp/dh with respect to change in h, may be expressed as
fB/(H - h)
fB/(H - h)2
fB/(H + h)
fB/(H + h)2
If the image of a triangulation station of R.L. 500 m is 4 cm from the principal point of a vertical photo taken from an altitude of 2000 m, above datum, the height displacement will be
2 mm
4 mm
6 mm
10 mm
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 correction for parallax, is
- 8.8 cos α
+ .8 sin α
+ 8.8 cos α
- 8.8 cos α