If the distance between the projectors is altered by a movement along X-axis of one projector,
The length of the air base is increased
The scale of the model is altered
y-parallax is not affected
All the above
Correct Answer :
D. All the above
Related Questions
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
Pick up the correct statement from the following:
The horizontal direction of the pole is called astronomical north
The angle between the direction of true north and the direction of a survey line is called astronomical bearing
The astronomical bearing is generally called azimuth
All the above
Pick up the incorrect statement from the following:
In truly vertical photographs without relief angles are true at the plumb point
In tilted photographs without relief, angles are true at the iso-centre
In tilled photographs with relief, angles are true at the principal point
None of these
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
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
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
The main object of the astronomer to obtain
Astronomical latitude
Astronomical longitude
Astronomical bearing
All of these
To have greatest coverage of the area, the type of photography used, is
High oblique
Low oblique
Vertical
None of these
International Date Line is located along
Standard meridian
Greenwich meridian
Equator
180° longitude
In a tropical year, the numbers of sidereal days are
One less than mean solar days
One more than mean solar days
Equal to mean solar days
None of these
23 cm × 23 cm photographs are taken from a flying height with a camera of focal length of 3600 m and 15.23 cm respectively. A parallax difference of 0.01 mm represents
1 m
2 m
4 m
8 m
The shortest distance between two places measured along the surface of the earth, is
Length of the equator between their longitudes
Length of the parallel between their longitudes
Length of the arc of the great circle passing through them
None of these
Pick up the correct statement from the following:
The sun's right ascension increases for 0 h to 24 h when it returns to the First point of Aries
The maximum declination of the sun increases up to 23 ½° N on about 21st June
The minimum declination of the sun is zero' on 22nd September
All the above
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
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
G.M.T. corresponding to given mean time, equals
L.M.T. - East longitude in time
L.M.T. + East longitude in time
L.M.T. - West longitude in time
None of these
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
Stellar astronomy deals with
Plane surveying
Geodetic surveying
Star observations
Planet observations
The principal plane contains
Nadir point
Iso centre
Principal point
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
In a spherical triangle ABC, right angled at C, sin b equals
sin a cos A
cos a sin A
tan a cot A
cot A tan a
α and β are the angles subtended by a point of elevation h at their air station with respective plumb points. Photo scale and focal length of the lens being S and f respectively. Parallax displacement of the point due to relief, is
h tan α/S
h tan β/S
h (tan α + tan β)/S
h (tan α - tan β)/S
Pick up the correct statement from the following:
The vertical plane containing the zenith, the station of observation and the celestial pole is the observer's meridian plane
The angle between the direction of star in vertical plane and the direction of the star in horizontal plane is called the altitude of the star
The complement of the altitude of star is called the zenith distance of the star
All the above
Parallax bar measures
Parallax
Height
Parallax difference
Height difference
Pick up the correct statement from the following:
North end of the polar axis is known as North Pole
South end of the polar axis is known as South Pole
Point where polar axis when produced northward intersects the celestial sphere, is known as north celestial pole
All the above
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 point where a vertical line through the optical centre of the camera lens intersects the ground, is known as
Ground principal point
Ground plumb point
Iso-centre
Perspective centre
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 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
The negative sign is assigned to
Reduction to mean sea level
Correction for horizontal alignment
Correction for slope
All the above