A star in northern sphere is said to transit
When its altitude is maximum
When its azimuth is 180°
When it is in south
All the above
Correct Answer :
D. All the above
Related Questions
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 principal line is the line joining the principal point and
Nadir
Isocenter
Perspective centre
None of these
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
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
The true and mean suns occupy the same meridian at the same time on
April 15
June 14
September 1
All the above
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°
The great circle along which the sun appears to trace on the celestial sphere with earth as centre during the year, is called
Equator
Celestial equator
Ecliptic
None of these
The normal longitudinal overlap is generally kept
50 %
60 %
70 %
75 %
The rate of change of parallax dp/dh with respect to change in h, may be expressed as
fB/(H - h)
fB/(H - h)2
fB/(H + h)
fB/(H + h)2
While making astronomical observations, the observer is mainly concerned with
The direction of the vertical, the axis of rotation of the instrument
The direction of the poles of the celestial sphere
The direction of the star from the instrument
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°
The moon rotates round the earth once in every
29 days
29.35 days
29.53 days
30 days
The great circle which passes through the zenith, nadir and the poles, is known as
Meridian
Vertical circle
Prime vertical
None of these
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 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
The point on the photograph where bisector between the vertical line through optical centre of the camera lens and the plate perpendicular meets, is known as
Principal point
Isocenter
Plumb point
Perspective centre
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 negative sign is assigned to
Reduction to mean sea level
Correction for horizontal alignment
Correction for slope
All the above
With standard meridian as 82° 30' E the standard time at longitude 90° E is 8 h 30 m. The local mean time at the place will be
7 h 00 m
7 h 30 m
8 h 00 m
9 h 00 m
The correction applied to the measured base of length L is
Tension = (P - Ps)L/AE
Sag = L3w²/24P² where w is the weight of tape/m
Slope = (h²/2L) + (h4/8L3) where h is height difference of end supports
All the above
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
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 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
If S is the sum of three angles of a spherical triangle, the spherical excess equals
S - 90°
S - 180°
S - 270°
S - 360°
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
If E is the spherical excess and R the radius of the earth, the surface area of the triangle, is
πR²E/90°
πR²E/180°
πR²E/270°
πR²E/360°
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
The foot of the perpendicular on the picture plane through the optical centre of the camera lens, is known as
Isocenter
Principal point
Perspective centre
Plumb line
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
Pick up the incorrect statement from the following. High oblique photographs
May have tilt up to 30°
May include the image of the horizon
May not include the image of the horizon
None of these