In field astronomy, the quantities observed are entirely
Lengths
Angles
Heights
All of these
Correct Answer :
B. Angles
Related Questions
The sidereal day is the time interval between two successive upper transits of
Mean sun
First point of Aries
First point of Libra
The polar star
If 16 flight lines are run perpendicular to an area 30 km wide, their spacings on a photographical map on scale 1 : 50,000 , will be
1 cm
2 cm
3 cm
4 cm
If f is the focal length of the camera lens and θ is the angle of tilt, the distance of the plumb point from the principal point will be
f sin θ
f cos θ
f tan θ
f sec θ
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 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)
The nautical mile is the length of
1 minute of latitude
1 minute of longitude
1 degree of latitude
1 degree of longitude
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
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
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 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 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
For mapping any country
Geodetic triangulation of greatest possible sides and accuracy is carried out
Primary triangles are broken down into secondary triangles of somewhat lesser accuracy
Secondary triangles are further broken into third and fourth order triangles, the points of which are used for detail surveys
All the above
The great circle which passes through the zenith, nadir and the poles, is known as
Meridian
Vertical circle
Prime vertical
None of these
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 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
The sun's declination remains north between
March 21 to June 21
June 21 to September 21
September 21 to December 21
Both (a) and (b) of above
The angle between the axis of earth and the vertical at the station of observation is called
Astronomical latitude
Astronomical co-latitude
Co-declination of star
Declination of star
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
International Date Line is located along
Standard meridian
Greenwich meridian
Equator
180° longitude
The equation which is obtained by multiplying each equation by the coefficient of its un-knowns and by adding the equations thus formed, is known as
Observation equation
Conditional equation
Normal equation
None of these
The net ground area of a vertical photograph 20 cm × 20 cm on scale 1 : 10,000 having overlaps 60% and 30%, is
0.50 sq km
0.56 sq km
0.60 sq km
0.64 sq km
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
The point where a vertical line through the optical centre of the camera lens intersects the ground, is known as
Ground principal point
Ground plumb point
Iso-centre
Perspective centre
Rotation of the camera at exposure about its vertical axis, is known as
Swing
Tilt
Tip
None of these
In a truly vertical photograph,
Principal point coincides the isocenter
Iso-centre coincides the plumb point
Plumb point coincides the principal point
All the above
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 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 from the following:
The horizontal direction of the pole is called astronomical north
The angle between the direction of true north and the direction of a survey line is called astronomical bearing
The astronomical bearing is generally called azimuth
All the above
The stereo plotting instruments are generally manufactured on the principle of
Optical projection
Optical mechanism projection
Mechanical projection
All the above
The station which is selected close to the main triangulation station, to avoid intervening obstruction, is not known as
Satellite station
Eccentric station
False station
Pivot station