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)
Correct Answer :
B. Parallel to base line
Related Questions
If a star whose declination is 60° N culminates at zenith, its altitude at the lower culmination, is
10°
20°
30°
40°
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
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 Polaris remains below horizon at
10° N
50° N Latitude
Equator
5° S latitude
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
An aerial photograph may be assumed as
Parallel projection
Orthogonal projection
Central projection
None of these
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°
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 distance between the projection centre and the photograph, is called
Principal distance
Principal line
Isocentric distance
Focal length
If the distance between the projectors is altered by a movement along X-axis of one projector,
The length of the air base is increased
The scale of the model is altered
y-parallax is not affected
All the above
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 position of a heavenly body on the celestial sphere can be completely specified by
Its altitude and azimuth
Its declination and hour angle
Its declination and right ascension
All the above
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
In field astronomy, the quantities observed are entirely
Lengths
Angles
Heights
All of these
Perspective centre relates to
Parallel projection
Orthogonal projection
Central projection
None of these
The declination and right ascension of the sun becomes 23° 27' N and 90° respectively on
March 21
June 21
September 21
December 22
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
The shortest distance between two places measured along the surface of the earth, is
Length of the equator between their longitudes
Length of the parallel between their longitudes
Length of the arc of the great circle passing through them
None of these
The angular distance of a heavenly body from the equator, measured along its meridian, is called
Declination
Altitude
Zenith distance
Co-latitude
If θ and δ be the latitude of an observer and declination of a heavenly body respectively, the upper culmination of the body will be south of zenith if its zenith distance, is
δ - θ
θ - δ
θ + δ
½ (θ - δ)
The main object of the astronomer to obtain
Astronomical latitude
Astronomical longitude
Astronomical bearing
All of these
Right ascension of a heavenly body is its equatorial angular distance measured
Westward from the first point of Libra
Eastward from the first point of Aeries
Westward from the first point of Aeries
Eastward from the first point of Libra
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
The station pointer is generally used in
Triangulation surveying
Astronomical surveying
Hydrographical surveying
Photogrammetric surveying
The value of geo-centric parallax to be added to the observed altitude of sun is
9 cos α
9 sin α
9 tan α
9 cot α
The method of surveying by triangulation was first introduced by the Dutchman Snell in
1600
1615
1630
1650
Systematic errors
Always follow some definite mathematical law
Can be removed by applying corrections to the observed values
Are also known as cumulative errors
All the above
Triangulation surveys are carried out for providing
Planimetric control
Height control
Both planimetric and height control
None of these
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 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