The altitude of a circumpolar star is maximum when it is
At east elongation
At upper culmination
At west elongation
At lower culmination
Correct Answer :
B. At upper culmination
Related Questions
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 declination and right ascension of the sun becomes 23° 27' N and 90° respectively on
March 21
June 21
September 21
December 22
Limiting gradient for locating the base line on evenly-sloping ground, is
1 in 12
1 in 10
1 in 8
1 in 6
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
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
The scale of a tilted photograph of focal length f taken from an altitude H, along the plate parallel through principal point is
f/H sec θ
f sec θ/H
f/H
f/H cos ½θ
The altitude of a circumpolar star is maximum when it is
At east elongation
At upper culmination
At west elongation
At lower culmination
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
Places having same latitude
Lie on the parallel of the latitude
Are equidistant from the nearer pole
Are equidistant from both the poles
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
The principal line is the line joining the principal point and
Nadir
Isocenter
Perspective centre
None of these
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
The plane at right angle to the zenith-nadir line and passing through the centre of the earth, is called
Rational horizon
True horizon
Celestial horizon
All the above
The declination and right ascension of the sun becomes 23° 27' S and 270° respectively on
March 21
June 21
September 21
December 22
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
The most convenient co-ordinate system for specifying the relative positions of heavenly bodies on the celestial sphere, is
Altitude and azimuth system
Declination and hour angle system
Declination and right ascension system
Declination and altitude system
Pick up the correct statement from the following:
The vertical plane containing the zenith, the station of observation and the celestial pole is the observer's meridian plane
The angle between the direction of star in vertical plane and the direction of the star in horizontal plane is called the altitude of the star
The complement of the altitude of star is called the zenith distance of the star
All the 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
A plate parallel is the line on the plane of the negative
Parallel to the principal line
Perpendicular to the principal line
Along the bisector of the angle between the principal line and a perpendicular line through principal plane
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
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 elevation of the star at elongation is obtained by
sin α = sin φ cosec δ
sin α = sin φ sec δ
sin α = cos φ sec δ
sin α = cos φ cosec δ
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
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 following points form a pair of homologous points:
Photo principal point and ground principal point
Photo isocenter and ground isocenter
Photo plumb point and ground plumb point
All the above
At western elongation, the pole star moves
Eastward
Westward
Northward
Southward
Pick up the in-correct statement from the following:
Correction for refraction is always negative
Correction for parallax is always positive
Correction for semi-diameter is always negative
Correction for dip is always negative
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
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
Pick up the correct statement from the following:
The star's movement is apparent due to the actual steady rotation of the earth about its axis
The stars move round in circular concentrated parts
The centre of the circular paths of stars is the celestial pole
All the above