Sidereal day
Is the period of time taken by the earth in making a complete rotation with reference to stars
Is slightly shorter than an ordinary solar day
Is divided into the conventional hours, minutes and seconds
All the above
Correct Answer :
D. All the above
Related Questions
For plane ground the scale of a vertical photograph will be same as that of a tiled photograph along the photo parallel through
Isocenter
Plumb point
Principal point
None of these
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 point on the celestial sphere vertically below the observer's position, is called
Zenith
Celestial point
Nadir
Pole
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 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 Polaris remains below horizon at
10° N
50° N Latitude
Equator
5° S latitude
To obtain photographs of an area of 1000 m average elevation, on scale 1 : 30, 000, with a camera of 30 cm focal length, the flying height is
4000 m
5000 m
6000 m
7000 m
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
At lower culmination, the pole star moves
Eastward
Westward
Northward
Southward
On vertical photographs, height displacement is
Positive for points above datum
Negative for points below datum
Zero for points vertically below the air station
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
If a star whose declination is 60° N culminates at zenith, its altitude at the lower culmination, is
10°
20°
30°
40°
The negative sign is assigned to
Reduction to mean sea level
Correction for horizontal alignment
Correction for slope
All the above
A star is said to elongate
When the star momentarily moves vertically
When the angle at the star of the spherical triangle is 90°
When the star's declination is greater than the observer's latitude
All the above
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
Triangulation surveys are carried out for locating
Control points for surveys of large areas
Control points for photogrammetric surveys
Engineering works, i.e. terminal points of long tunnels, bridge abutments, etc.
All the above
The scale of the photography taken from a height of 300 m, with a camera of focal length 15 cm, is
1 : 10,000
1 : 15,000
1 : 20,000
1 : 30,000
Spring tides are caused when
Sun and moon are in line with earth
Solar tidal force acts opposite to lunar tidal force
Solar tidal force and lunar tidal force both coincide
None of these
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
The station pointer is generally used in
Triangulation surveying
Astronomical surveying
Hydrographical surveying
Photogrammetric surveying
The height displacement on a vertical photograph
Increases as the horizontal distance increases from the principal point
Increases as the ground elevation increases
Decreases as the flying height increases
All the above
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°
Invar tapes used for measuring base lines, is made of nickel-iron alloy containing nickel
24 %
36 %
40 %
60 %
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 nearest star is so far away from the earth that the directions to it from two diametrically opposite points on the earth differs less than
0.01 second
0.001 second
0.0001 second
None of these
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
For any star to be a circumpolar star, its
Declination must be 0°
Declination must be 90°
Distance from the pole must be less than the latitude of the observer
Hour angle must be 180°
Stellar astronomy deals with
Plane surveying
Geodetic surveying
Star observations
Planet observations
The declination and right ascension of the sun becomes 23° 27' S and 270° respectively on
March 21
June 21
September 21
December 22
Pick up the correct statement from the following:
The measured stereoscopic base of photographs is obtained by dividing the air base in metres by the mean scale of the photograph
The difference between the absolute parallax of two points depends upon the difference in their elevations
The line joining the principal point of a photograph and the transferred principal point of the adjoining photograph, is called stereoscopic base
All the above