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
Correct Answer :
B. 1000 m
Related Questions
Pick up the in-correct statement from the following:
Apparent solar time is measured from the lower transit of the true sun
Mean solar time is measured from the lower transit of the mean sun
Sidereal time is measured from the lower transit of the first point of Aries
Sidereal time is measured from the upper transit of the first point of Aries
The latitude of a place was obtained by subtracting the zenith distance of a star from its declination, the observed star was between
Horizon and equator
Equator and zenith
Zenith and pole
Pole and horizon
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 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
H is the flying height above mean ground level and f is the principal distance of a vertical photograph. The mean scale of the photographs is
H. f
H/f
f/H
H + f
In a tropical year, the numbers of sidereal days are
365
365.2224
365.2422
366.2422
The normal longitudinal overlap is generally kept
50 %
60 %
70 %
75 %
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
Spring tides are caused when
Sun and moon are in line with earth
Solar tidal force acts opposite to lunar tidal force
Solar tidal force and lunar tidal force both coincide
None of these
Pick up the correct statement from the following:
The measured stereoscopic base of photographs is obtained by dividing the air base in metres by the mean scale of the photograph
The difference between the absolute parallax of two points depends upon the difference in their elevations
The line joining the principal point of a photograph and the transferred principal point of the adjoining photograph, is called stereoscopic base
All the above
If a star whose declination is 60° N culminates at zenith, its altitude at the lower culmination, is
10°
20°
30°
40°
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 scale of the photography taken from a height of 300 m, with a camera of focal length 15 cm, is
1 : 10,000
1 : 15,000
1 : 20,000
1 : 30,000
The stereo plotting instruments are generally manufactured on the principle of
Optical projection
Optical mechanism projection
Mechanical projection
All the above
The moon rotates round the earth once in every
29 days
29.35 days
29.53 days
30 days
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 from the following:
If the applied tension to the tape is more than the standard, the tension correction is positive
If the applied tension to the tape is less than the standard, the tension correction is negative
If the temperature during measurement is greater than the standard temperature, the temperature correction is positive
All the above
The nearest star is so far away from the earth that the directions to it from two diametrically opposite points on the earth differs less than
0.01 second
0.001 second
0.0001 second
None of these
The scale of a vertical photograph of focal length f taken from height of H metres above M.S.L., at a point of reduced level h, is
f/H
f/(H + h)
f/(H - h)
(H - h)/f
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
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 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'
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
For plane ground the scale of a vertical photograph will be same as that of a tiled photograph along the photo parallel through
Isocenter
Plumb point
Principal point
None of these
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
Pick up the incorrect statement from the following:
Latitudes north of the equator are taken as positive
Latitudes south of the equator are taken as negative
Longitudes east of Greenwich are taken as negative
Longitudes west of Greenwich are taken as positive
If δ is the declination of the star and φ is the latitude of the observer then the hour angle of the star at elongation is given by
sin H = tan φ . cot δ
cos H = tan φ . cot δ
tan H = tan φ . cot δ
None of these
Latitude of the observer's position is equal to altitude of
North pole
Pole star
Celestial pole
All the above
The want of correspondence in stereo-photographs
Is a good property
Is a function of tilt
Is not affected by the change of flying height between photographs
Is minimum when θ is 3°
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