The scale of a tilted photograph of focal length f, taken from an altitude H, along the plate parallel through plumb point, is
f/H sec θ
f sec θ/H
f/H
f/H cos ½θ
Correct Answer :
B. f sec θ/H
Related Questions
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
Rotation of the camera at exposure about horizontal axis normal to the line of flight, is known as
Swing
Tilt
Tip
None of these
In a tropical year, the numbers of sidereal days are
365
365.2224
365.2422
366.2422
The sun's declination remains north between
March 21 to June 21
June 21 to September 21
September 21 to December 21
Both (a) and (b) of above
If S is the sum of three angles of a spherical triangle, the spherical excess equals
S - 90°
S - 180°
S - 270°
S - 360°
The great circle which passes through the zenith, nadir and the poles, is known as
Meridian
Vertical circle
Prime vertical
None of these
To have greatest coverage of the area, the type of photography used, is
High oblique
Low oblique
Vertical
None of these
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
Pick up the correct statement from the following:
The angle between the plane of the negative and the horizontal plane containing perspective axis is the tilt of the photograph
The direction of maximum tilt is defined by the photo principal line
The principal plane is truly vertical plane which contains perspective centre as well as principal point and plumb point
All the above
The difference of parallax for a given difference in elevation is independent of
Focal length of the camera
Overall size of the photo graphs
Percentage of overlap
All the above
To obtain photographs of an area of 1000 m average elevation, on scale 1 : 30, 000, with a camera of 30 cm focal length, the flying height is
4000 m
5000 m
6000 m
7000 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
The sidereal day is the time interval between two successive upper transits of
Mean sun
First point of Aries
First point of Libra
The polar star
The distance between the projection centre and the photograph, is called
Principal distance
Principal line
Isocentric distance
Focal length
If α is the observed altitude, the refraction correction in seconds, is
58 cot α
58 tan α
58 sin α
58 cos α
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
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 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
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
For any star to be a circumpolar star, its
Declination must be 0°
Declination must be 90°
Distance from the pole must be less than the latitude of the observer
Hour angle must be 180°
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 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
The nautical mile is the length of
1 minute of latitude
1 minute of longitude
1 degree of latitude
1 degree of longitude
The declination and right ascension of the sun becomes 23° 27' S and 270° respectively on
March 21
June 21
September 21
December 22
The point on the celestial sphere vertically below the observer's position, is called
Zenith
Celestial point
Nadir
Pole
The great circle whose plane is perpendicular to the axis of rotation of the earth, is called
Equator
Terrestrial equator
0° latitude
All the above
From the principal point the horizon point lies on the principal line at a distance of
f tan θ
f sin θ
f cot θ
f cos θ
The product of the distances of plumb point and horizon point of a vertical photograph from its principal point, is
f2
2f2
3f2
½f
The point at which sun's declination changes from north to south, is known as
First point of Aeries
First point of Libra
Vernal Equinox
Both (b) and (d) of 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