If α, H, A and δ be the altitude, hour angle, azimuth and declination of a circumpolar star at its elongation, in latitude λ, the following relation holds good
cos H = tan λ/tan δ
sin α = sin λ/sin δ
sin A = cos δ/cos λ
All the above
Correct Answer :
D. All the above
Related Questions
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
Invar tapes used for measuring base lines, is made of nickel-iron alloy containing nickel
24 %
36 %
40 %
60 %
Pick up the correct statement from the following:
North end of the polar axis is known as North Pole
South end of the polar axis is known as South Pole
Point where polar axis when produced northward intersects the celestial sphere, is known as north celestial pole
All the above
At the first point of Aeries, the sun moves
Northward
Southward
From south to north of the equator
From north to south of the equator
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
Pick up the correct statement from the following:
Sidereal time at any instant is equal to the hour angle of the first point of Aries
Local sidereal time of any place is equal to the right ascension of its meridian
Sidereal time is equal to the right ascension of a star at its upper transit
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 difference of height of two points whose parallax difference is 0.8 mm on a pair of stereo pair taken from a height H is 100 m. If mean photo base is 95.2 mm, the flying height is
8,000 m
10,000 m
12,000 m
14,000 m
Perspective centre relates to
Parallel projection
Orthogonal projection
Central projection
None of these
The stereo plotting instruments are generally manufactured on the principle of
Optical projection
Optical mechanism projection
Mechanical projection
All the above
The nautical mile is the length of
1 minute of latitude
1 minute of longitude
1 degree of latitude
1 degree of longitude
Pick up the correct statement from the following:
Refraction correction is zero when the celestial body is in the zenith
Refraction correction is 33' when the celestial body is on the horizon
Refraction correction of celestial bodies depends upon their altitudes
All the above
Pick up the correct statement from the following:
The plane passing through the perspective centre of a stereo pair and a ground point, is known as basal plane
Each pair of image points on stereo pair have their own basal plane
Relative orientation means reconstructing the basal plane
All the above
If the altitudes of a star at its upper and lower transits are 60° 30' and 19° 30' respectively, the latitude of the place, is
30°
35°
40°
45°
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
At eastern elongation, the pole star moves
Eastward
Westward
Northward
Southward
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)
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 α is the observed altitude, the refraction correction in seconds, is
58 cot α
58 tan α
58 sin α
58 cos α
The Polaris remains below horizon at
10° N
50° N Latitude
Equator
5° S latitude
The great circle whose plane is perpendicular to the axis of rotation of the earth, is called
Equator
Terrestrial equator
0° latitude
All the above
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
Pick up the correct statement from the following:
The principal point coincides with plumb point on a true vertical photograph
The top of a hill appears on a truly vertical photograph at greater distance than its bottom from the principal point
The top of a hill is represented on a vertical photograph at larger scale than the area of a nearby valley
All the above
If v, t and f/H are the ground speed of the aircraft, the shutter speed of the camera and the scale of the photograph respectively, then the amount of image displacement
i = v. t. H/f
i = v. f/t. H
i = v. t. (f/H)
i = t. H/v. f
G.M.T. corresponding to given mean time, equals
L.M.T. - East longitude in time
L.M.T. + East longitude in time
L.M.T. - West longitude in time
None of these
The angle between the plane of the equator and the plane of the ecliptic, is known as obliquity of the ecliptic and its value is
22° 30'
23° 27'
23° 30'
24° 0'
At upper culmination, the pole star moves
Eastward
Westward
Northward
Southward
When a star is between the pole and the horizon, the relationship between latitude (λ), zenith distance (z) and declination δ, is
θ = z + δ
θ = δ - z
θ = 180° - (z + δ)
θ = (z + δ) - 180°
If a star whose declination is 60° N culminates at zenith, its altitude at the lower culmination, is
10°
20°
30°
40°
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