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
Correct Answer :
C. 72 m
Related Questions
If θ and δ be the latitude of an observer and declination of a heavenly body respectively, the upper culmination of the body will be south of zenith if its zenith distance, is
δ - θ
θ - δ
θ + δ
½ (θ - δ)
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
Circumpolar stars
Rotate round the North Pole
Rotate round the celestial pole
Remain always above the horizon
Are seldom seen near the pole star
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 correction for parallax, is
- 8.8 cos α
+ .8 sin α
+ 8.8 cos α
- 8.8 cos α
The circle in which a plane tangent to the earth's surface at the point of observation, intersects the celestial sphere, is called
Visible horizon
Sensible horizon
Celestial horizon
True horizon
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 principal line is the line joining the principal point and
Nadir
Isocenter
Perspective centre
None of these
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
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
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
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
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 position of a heavenly body on the celestial sphere can be completely specified by
Its altitude and azimuth
Its declination and hour angle
Its declination and right ascension
All the above
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
Pick up the incorrect statement from the following. The angular distance of heavenly bodies on observer's meridian measured from the pole, is
Co-declination
Co-altitude
Co-latitude
Polar distance
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
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
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
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
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
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
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 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 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
The relation between the air base (B), photographic base (b), flying height (H) and the focal length (f) of a vertical photograph, is
B = bH/f
B =f/bH
B = b/fH
B = H/bf
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
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
If the equatorial distance between two meridians is 100 km, their distance at 60° latitude will be
1000 km
800 km
600 km
500 km
The latitude of a place was obtained by subtracting the declination of a star from its zenith distance, the observed star was between
Horizon and equator
Zenith and pole
Equator and zenith
Pole and horizon