1.Find the correction for curvature for a distance 2.48 km?
a) 0.483 m
b) 0.434 m
c) 0.443 m
d) 0. 403 m
Explanation: Correction for curvature is 0.07849 d2. Therefore, here 0.07849*(2.48)2 = 0.483 m.
2. Find correction for refraction for a distance of 2.48 km?
a) 0.0066 m
b) 0.0160 m
c) 0.069 m
d) 0.096 m
Explanation: Correction for refraction is correction for curvature/7. Therefore, here (0.07849 * (2.48)2)/7 = 0.069 m.
3. Find combined correction for curvature and refraction for 3400 m?
a) 0.078 m
b) 0.778 m
c) 0.709 m
d) 0.786 m
Explanation: Combined correction for curvature and refraction is given by 0.06728 d2. Therefore, here 0.06728 (3.4)2 = 0.778 m
4. Find combined correction for curvature and refraction for 1.29 km?
a) 0.112 m
b) 0.128 m
c) 0.212m
d) 0.221 m
Explanation: Combined correction for curvature and refraction is given by 0.06728 d2. Therefore, here, 0.06728(1.29)2 = 0.112 m.
5. In order to find the difference in elevation between two points P and Q, a level was set upon the line PQ, 30 m from P and 1280 m from Q. The reading obtained on staff kept at P and Q were respectively 0.545 m and 3.920 m. Find the true difference in elevation between P and Q?
a) 3.226 m
b) 3.343 m
c) 3.265 m
d) 3.345 m
Explanation: Since the distance of P from an instrument is small, the correction for curvature etc is negligible. Combined correction for Q is 0.06728 (1.28)2 = 0.110 m. Correct staff reading at Q = 3.920 – 0.110 = 3.810 m. Difference in elevation between P and Q = 3.810 – 0.545 = 3.265 m.
6. A light house is visible just above the horizon at a certain station at the sea level. The distance between the station and light house is 10 km. Find the height of the light house?
a) 0 6728 m
b) 0.06728 m
c) 67.280 m
d) 6.728 m
Explanation: Combined correction for curvature and refraction is given by 0.06728 d2. Therefore, here 0.06728 (10)2 = 6.728 m.
7. Which of the following is not an instrumental error?
a) error due to imperfect adjustment
b) error due to sluggish bubble
c) error due to movement of objective slide
d) settlement of tripod or turning points
Explanation: Error due to imperfect adjustment, error due to sluggish bubble, error due to movement of the objective slide are instrumental errors. Settlement of tripod or turning points is a natural error.
8. Which of the following is a natural error?
a) error due to defective joint
b) rod not of standard length
c) variations in temperature
d) error due to sluggish bubble
Explanation: Error due to a defective joint, rod not of standard length, error due to sluggish bubble are instrumental errors. Variations in temperature are a natural error.
9. Which of the following is a personal error?
a) mistakes in manipulation
b) atmospheric refraction
c) settlement of tripod or turning points
d) wind vibrations
Explanation: Atmospheric refraction, settlement of tripod or turning points, wind vibrations are natural errors. Mistakes in manipulation is a personal error.
10. Which of the following is not a personal error?
a) mistake in rod handling
b) errors in sighting
c) mistake in reading the rod
d) error due to defective joint
Explanation: Mistake in rod handling, errors in sighting, a mistake in reading the rod are personal errors. Error due to the defective joint is an instrumental error.