81. A metallic tape is made of ______________ ? A. steel B. invar C. linen D. cloth and wires ✅ The correct answer is option D.
82. Subtense bar is an instrument used for _______________? A. levelling B. measurement of horizontal distances in plane areas C. measurement of horizontal distances in undulated areas D. measurement of angles ✅ The correct answer is option C.
83. In the double application of principle of reversion, the apparent error is_______________? A. equal to true error B. half the true error C. two times the true error D. four times the true error ✅ The correct answer is option D.
84. The following sights are taken on a “turning point”________________? A. foresight only B. backsight only C. foresight and backsight D. foresight and intermediate sight ✅ The correct answer is option C.
85. Agate cap is fitted with a_________________? A. cross staff B. level C. chain D. prismatic compass ✅ The correct answer is option D.
86. Which of the following is not the function of levelling head ? A. to support the main part of the instrument B. to attach the theodolite to the tripod C. to provide a means for leveling the theodolite D. none of the above ✅ The correct answer is option D.
87. Horizontal distances obtained by thermometric observations_________________? A. require slope correction B. require tension correction C. require slope and tension corrections D. do not require slope and tension corrections ✅ The correct answer is option D.
88. Which of the following errors cannot be eliminated by taking both face observations ? A. error due to horizontal axis not being perpendicular to the vertical axis B. index error i.e. error due to imperfect adjustment of the vertical circle vernier C. error due to non-parallelism of the axis of telescope level and line of collimation D. none of the above ✅ The correct answer is option D.
89. An imaginary line lying throughout the surface of ground and preserving a constant inclination to the horizontal is known as__________________? A. contour line B. horizontal equivalent C. contour interval D. contour gradient ✅ The correct answer is option D.
90. The allowable length of an offset depends upon the______________? A. degree of accuracy required B. method of setting out the perpendiculars and nature of ground C. scale of plotting D. all of the above ✅ The correct answer is option D.