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
Correct Answer :
C. Solar tidal force and lunar tidal force both coincide
Related Questions
Circumpolar stars
Rotate round the North Pole
Rotate round the celestial pole
Remain always above the horizon
Are seldom seen near the pole star
Pick up the correct statement for horizontal photographs.
Parallel lines do not appear parallel in central projection
The two sides of a road meet at the vanishing point
The lines parallel to the negative plane are projected as parallel lines
All the above
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 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)
Pick up the correct statement from the following. The difference between the longitudes of the places is obtained.
By subtracting their longitudes if places are in the same hemisphere
By adding their longitudes if places are in the different hemispheres
By subtracting the sum of their longitudes exceeding 180° from 360° if places are in different hemispheres
All the above
At lower culmination, the pole star moves
Eastward
Westward
Northward
Southward
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
The distance between the minor control point and the principal point should be equal to
Base line of the left photograph of stereo pair
Base line of the right photograph of stereo pair
Sum of the base lines of stereo pair
Mean of the base lines of the stereo pair
Invar tapes used for measuring base lines, is made of nickel-iron alloy containing nickel
24 %
36 %
40 %
60 %
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
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
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
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
Stellar astronomy deals with
Plane surveying
Geodetic surveying
Star observations
Planet observations
The parallax equation Δp = BmΔh/H - h is applicable to entire overlap of the photographs only if parallax is measured
Normal to base line
Parallel to base line
Both (a) and (b)
Neither (a) nor (b)
If E is the spherical excess and R the radius of the earth, the surface area of the triangle, is
πR²E/90°
πR²E/180°
πR²E/270°
πR²E/360°
The equation which is obtained by multiplying each equation by the coefficient of its un-knowns and by adding the equations thus formed, is known as
Observation equation
Conditional equation
Normal equation
None of these
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 distance between the projection centre and the photograph, is called
Principal distance
Principal line
Isocentric distance
Focal length
The altitude of a circumpolar star is maximum when it is
At east elongation
At upper culmination
At west elongation
At lower culmination
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°
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 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 following points form a pair of homologous points:
Photo principal point and ground principal point
Photo isocenter and ground isocenter
Photo plumb point and ground plumb point
All the above
The meridian of a place is
A great circle passing through the place and the poles
A great circle whose plane is perpendicular to the axis of rotation and it also passes through the place
A semi-circle which passes through the place and is terminated at the poles
An arc of the great circle which passes through the place and is perpendicular to the equator
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 station which is selected close to the main triangulation station, to avoid intervening obstruction, is not known as
Satellite station
Eccentric station
False station
Pivot station
Places having same latitude
Lie on the parallel of the latitude
Are equidistant from the nearer pole
Are equidistant from both the poles
All the above
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 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