MCQ
1841. A line joining the optical centre of the object glass & the centre of the eyepiece, is known as-
fundamental line
axis of telescope
axis of level tube
line of collimation
ব্যাখ্যা:
1842. The obstacle, which obstructs chaining but not vision, is a-
river
pond
hill
all of these
1843. If the fore bearing of a line is its back bearing will be
36°15′.
126°15′
143°45′
216°15′
1844. The image formed by the objective in the plane of the cross hair is-
real and straight
real and inverted
virtual and straight
virtual and inverted
1845. The axis of telescope level must be - to the line of collimation.
parallel
perpendicular
1846. When the magnetic bearing of the sun at noon is 185°20′, the magnetic declination will be-
5°20′ east
5°20′ west
5°20′ north
5°20′ south
1847. In the surveying telescopes, cross hairs are fitted in-
center of the telescope
optical center of the eye piece
front of the eye piece
front of the objective
ব্যাখ্যা:
1848. The obstacle, which obstructs vision but not chaining, is a-
river
pond
hill
all of these
1849. The angle between the reflecting surfaces of a prism square is-
30°
45°
60°
75°
1850. The lines of earth's magnetic field run from-
south to north
north to south
east to west
west to east
1851. In a whole circle bearing system N25°15′W corresponds to-
115°15′
154°45′
205°15′
334°45′
1852. If the fore bearing of a line is 36°15′, its back bearing will be-
36°15′
126°15′
143°45′
216°15′
ব্যাখ্যা: সম্মুখ বিয়ারিং ও পশ্চাৎ বিয়ারিং-এর মাঝে পার্থক্য ১৮০০ হয়।
1853. At the equator, the amount of dip is-
0°
45°
60°
90°
1854. An open cross-staff is commonly used for setting out-
short offsets
long offsets
oblique offsets
none of these
1855. A French cross-staff has a magnetic compass at the top.
Right
Wrong
1856. In a prismatic compass, the zero of the graduated ring is located at-
north end
east end
south end
west end
1857. The horizontal angle between the true meridian and magnetic meridian is known as-
true bearing
dip
local attraction
magnetic declination
1858. The capacity of a telescope producing a sharp image is called its-
definition
brightness
sensitivity
magnification
1859. An axis about which the telescope can be rotated in a horizontal plane, is called-
horizontal axis
vertical axis
axis of the level tube
line of collimation
1860. The angle of intersection of the horizon glass and index glass in an optical square is-
30°
45°
60°
75°