The product of the distances of plumb point and horizon point of a vertical photograph from its principal point, is
f2
2f2
3f2
½f
Correct Answer :
A. f2
Related Questions
The latitude (λ) of a place and the altitude (α) of the pole are related by
λ = α
λ = 90° - α
λ = α - 90°
λ = 180° - α
In triangulation surveys
The area is divided into triangular figures
Control stations are located from which detailed surveys are carried out
Sides are not measured excepting the base line
All the above
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
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 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°
Pick up the correct statement from the following:
Ursa Minor's remains always north of pole star
Polar star remains always north of Polaris
Polaris remains always north of Ursa Minor's
Ursa Minor's pole star and Polaris are the names of the same star
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 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 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 zenith is the point on the celestial sphere
East of observer
West of observer
North of observer
South of observer
Longitude of a place is the angular distance between the meridian of the place and
The standard meridian
The international date line
That of Greenwich
Both (a) and (c) of 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
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
International Date Line is located along
Standard meridian
Greenwich meridian
Equator
180° longitude
The solar tidal force divided by lunar tidal force is
1/3
1/2
3/4
5/4
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 relief displacement of a building 72 m high on photograph is 7.2 mm and its top appears 10 cm away from principal point. The flying height of the camera, is
500 m
1000 m
1500 m
2000 m
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
The average eye base is assumed as
58 mm
60 mm
62 mm
64 mm
The distance between the projection centre and the photograph, is called
Principal distance
Principal line
Isocentric distance
Focal length
If S is the sum of three angles of a spherical triangle, the spherical excess equals
S - 90°
S - 180°
S - 270°
S - 360°
If θ and δ be the latitude of a place and declination of a star respectively, the upper culmination of the star will be north of zenith if its zenith distance, is
δ - θ
θ - δ
θ + δ
(θ + δ)/2
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°
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 parallax of a point on the photograph is due to
Ground elevation
Flying height
Length of air base
All the above
If δ is the declination of the star and φ is the latitude of the observer, then the azimuth of the star at elongation is given by
sin z = sec φ . cos δ
cos z = sec φ . cos δ
tan z = sec φ . cos δ
None of these
The position of the sun when its north declination is maximum is known as
Vernal equinox
Autumnal equinox
Summer solstice
Winter solstice
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 negative sign is assigned to
Reduction to mean sea level
Correction for horizontal alignment
Correction for slope
All the above
The hour angle of the heavenly body for Greenwich meridian equals the hour angle of the body for any other meridian + longitude:
Mean sun
True sun
Vernal equinox
All the above