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
Correct Answer :
D. Both (b) and (d) of the above
Related Questions
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 scale of a vertical photograph of focal length f taken from height of H metres above M.S.L., at a point of reduced level h, is
f/H
f/(H + h)
f/(H - h)
(H - h)/f
The point where vertical line passing through the perspective centre intersects the plane of the photograph, is known as
Photo plumb point
Plumb point
Nadir point
Isocenter
The meridian of a place is
A great circle passing through the place and the poles
A great circle whose plane is perpendicular to the axis of rotation and it also passes through the place
A semi-circle which passes through the place and is terminated at the poles
An arc of the great circle which passes through the place and is perpendicular to the equator
The flying height of the camera is 1, 000 m above mean ground level, the distance of the top of a building from a nadir point is 10 cm and the relief displacement of building is 7.2 mm. The height of the building, is
52 m
62 m
72 m
82 m
International Date Line is located along
Standard meridian
Greenwich meridian
Equator
180° longitude
The principal plane contains
Nadir point
Iso centre
Principal point
All the above
The plane at right angle to the zenith-nadir line and passing through the centre of the earth, is called
Rational horizon
True horizon
Celestial horizon
All the above
The prime vertical passes through
The east point of the horizon
The west point of the horizon
The zenith point of the observer
All the above
The moon rotates round the earth once in every
29 days
29.35 days
29.53 days
30 days
The correction for parallax, is
- 8.8 cos α
+ .8 sin α
+ 8.8 cos α
- 8.8 cos α
The average eye base is assumed as
58 mm
60 mm
62 mm
64 mm
The parallax equation Δp = BmΔh/H - h is applicable to entire overlap of the photographs only if parallax is measured
Normal to base line
Parallel to base line
Both (a) and (b)
Neither (a) nor (b)
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
The angular distance of a heavenly body from the equator, measured along its meridian, is called
Declination
Altitude
Zenith distance
Co-latitude
If α is the observed altitude, the refraction correction in seconds, is
58 cot α
58 tan α
58 sin α
58 cos α
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 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 latitude of a place was obtained by subtracting the declination of a star from its zenith distance, the observed star was between
Horizon and equator
Zenith and pole
Equator and zenith
Pole and horizon
Pick up the correct statement from the following:
The star's movement is apparent due to the actual steady rotation of the earth about its axis
The stars move round in circular concentrated parts
The centre of the circular paths of stars is the celestial pole
All the above
In a spherical triangle ABC, right angled at C, sin b equals
sin a cos A
cos a sin A
tan a cot A
cot A tan a
Limiting gradient for locating the base line on evenly-sloping ground, is
1 in 12
1 in 10
1 in 8
1 in 6
If the equatorial distance between two meridians is 100 km, their distance at 60° latitude will be
1000 km
800 km
600 km
500 km
If a star whose declination is 60° N culminates at zenith, its altitude at the lower culmination, is
10°
20°
30°
40°
The main object of the astronomer to obtain
Astronomical latitude
Astronomical longitude
Astronomical bearing
All of these
Pick up the correct statement from the following:
One degree of longitude has greatest value at the equator
One degree of longitude has greatest value at the poles
One degree of longitude has the same value everywhere
One degree of latitude decreases from the equator to the poles
The point on the photograph where bisector between the vertical line through optical centre of the camera lens and the plate perpendicular meets, is known as
Principal point
Isocenter
Plumb point
Perspective centre
The altitudes of a circumpolar star at culminations are 70° and 10°, both culminations being north of zenith. The latitude of the place, is
80°
70°
60°
40°
If the general ground level of any area is 10% of the flying height, the principal points may be used as the centres of radial directions for small scale mapping even in tilted photograph up to
1°
2°
3°
4°
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