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
Correct Answer :
D. All the above
Related Questions
23 cm × 23 cm photographs are taken from a flying height with a camera of focal length of 3600 m and 15.23 cm respectively. A parallax difference of 0.01 mm represents
1 m
2 m
4 m
8 m
The difference in longitude of two places expressed in time is equal to the difference in their
Sidereal time
Apparent solar time
Mean solar time
All the above
The distance between the projection centre and the photograph, is called
Principal distance
Principal line
Isocentric distance
Focal length
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
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
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
An aerial photograph may be assumed as
Parallel projection
Orthogonal projection
Central projection
None of these
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
If δ is the declination of the Polaris and λ is the latitude of the place, the azimuth of the Polaris, is
cos δ/cos λ
cos (90° - δ)/cos (90° - λ)
sin (90° - δ)/sin (90° - λ)
tan (90° + δ)/tan (90° + λ)
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
Assuming human normal vision distance 25 cm, smallest measurable angle 20, and intraocular distance 6.5 cm, the smallest depth to be discerned is
0.1 mm
0.5 mm
1.00 mm
1.1 mm
Pick up the incorrect statement from the following. In a spherical triangle
Every angle is less than two right angles
Sum of the three angles is equal to two right angles
Sum of the three angles less than six right angles and greater than two right angles
Sum of any two sides is greater than the third
The distance between the minor control point and the principal point should be equal to
Base line of the left photograph of stereo pair
Base line of the right photograph of stereo pair
Sum of the base lines of stereo pair
Mean of the base lines of the stereo pair
The product of the distances of plumb point and horizon point of a vertical photograph from its principal point, is
f2
2f2
3f2
½f
The declination and right ascension of the sun becomes 23° 27' N and 90° respectively on
March 21
June 21
September 21
December 22
Pick up the correct statement from the following:
Centre of the celestial sphere is taken as the position of the observer
Centre of the celestial sphere is taken as the centre of the earth
Stars move and maintain their relative positions
All the above
The First Point of Aeries
Is the point in the celestial sphere where zero meridian crosses the celestial equator
Is usually denoted by the Greek letter γ
Is located near the very conspicuous rectangle of stars in the constellations of Pegasus and Andromeda
All the above
Homologous point is
Photo principal point
Ground principal point
Ground isocenter
All the above
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
While making astronomical observations, the observer is mainly concerned with
The direction of the vertical, the axis of rotation of the instrument
The direction of the poles of the celestial sphere
The direction of the star from the instrument
All the above
The angular distance of a heavenly body from the equator, measured along its meridian, is called
Declination
Altitude
Zenith distance
Co-latitude
Pick up the correct statement from the following. The difference between the longitudes of the places is obtained.
By subtracting their longitudes if places are in the same hemisphere
By adding their longitudes if places are in the different hemispheres
By subtracting the sum of their longitudes exceeding 180° from 360° if places are in different hemispheres
All the above
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
H is the flying height above mean ground level and f is the principal distance of a vertical photograph. The mean scale of the photographs is
H. f
H/f
f/H
H + f
The latitude of the observer's position, is
Elevation of the elevated pole
Declination of the observer's zenith
Angular distance along the observer's meridian between equator and the observer
All the above
The foot of the perpendicular on the picture plane through the optical centre of the camera lens, is known as
Isocenter
Principal point
Perspective centre
Plumb line
The correction for parallax, is
- 8.8 cos α
+ .8 sin α
+ 8.8 cos α
- 8.8 cos α
The orthogonal projection of the perspective centre on a tilted photograph, is called
Nadir
Isocenter
Principal point
Plumb point
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
A star may culminate at zenith if its declination is
Greater than the longitude of the place
Less than the latitude of the place
Equal to the latitude of the place
None of these