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A Theodolite is placed at A and a 3 m long vertical staff is held at B. The depression angle made at reading of 2.5m marking on staff is o 6 10'.The horizontal distance between A and B is 2200 m. The height of instrument at A is 1.2 m and reduced level of point A is 880.88 m. Using curvature correction and refraction correction determine the R.L. of point B (in m).
    Correct answer is between '641.9,642.3'. Can you explain this answer?
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    A Theodolite is placed at A and a 3 m long vertical staff is held at B...
    R.L. of A = 880.88m
    R.L. of Plane of Collimation = 880.88 + 1.2 = 882.08m
     
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    A Theodolite is placed at A and a 3 m long vertical staff is held at B...
    Solution:

    Given data:

    - The length of the vertical staff, AB = 3m
    - The depression angle at the 2.5m marking on the staff = 06°10'
    - The horizontal distance between A and B = 2200m
    - The height of instrument at A = 1.2m
    - The reduced level of point A = 880.88m

    To find:

    - The R.L. of point B

    1. Calculation of the angle of depression:

    The angle of depression can be calculated as:

    tan(06°10') = (1.2 - h) / 2200

    Where h is the height of point B above the datum.

    On solving, we get:

    h = 641.7m

    2. Calculation of curvature correction:

    The curvature correction can be calculated as:

    Cc = (D^2/2R)

    Where D is the distance between A and B and R is the radius of the earth.

    Assuming the radius of the earth to be 6370km, we get:

    R = 6370 x 1000m = 6370000m

    Cc = (2200^2 / 2 x 6370000) = 0.002m

    3. Calculation of refraction correction:

    The refraction correction can be calculated as:

    Cr = (0.13 / (1 + 0.004 / t)) x (P / 760)

    Where t is the temperature in degrees Celsius and P is the atmospheric pressure in mmHg.

    Assuming the temperature to be 20°C and the atmospheric pressure to be 760mmHg, we get:

    Cr = (0.13 / (1 + 0.004 / 20)) x (760 / 760) = 0.13 x 0.998 = 0.129m

    4. Calculation of the R.L. of point B:

    The R.L. of point B can be calculated as:

    R.L. of B = R.L. of A + (height of instrument at A) - (reading on staff) - Cc + Cr + h

    R.L. of B = 880.88 + 1.2 - 2.5 - 0.002 + 0.129 + 641.7 = 641.9m (approx)

    Therefore, the R.L. of point B is 641.9m (approx).
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    A Theodolite is placed at A and a 3 m long vertical staff is held at B. The depression angle made at reading of 2.5m marking on staff is o 6 10'.The horizontal distance between A and B is 2200 m. The height of instrument at A is 1.2 m and reduced level of point A is 880.88 m. Using curvature correction and refraction correction determine the R.L. of point B (in m).Correct answer is between '641.9,642.3'. Can you explain this answer?
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    A Theodolite is placed at A and a 3 m long vertical staff is held at B. The depression angle made at reading of 2.5m marking on staff is o 6 10'.The horizontal distance between A and B is 2200 m. The height of instrument at A is 1.2 m and reduced level of point A is 880.88 m. Using curvature correction and refraction correction determine the R.L. of point B (in m).Correct answer is between '641.9,642.3'. Can you explain this answer? for Civil Engineering (CE) 2024 is part of Civil Engineering (CE) preparation. The Question and answers have been prepared according to the Civil Engineering (CE) exam syllabus. Information about A Theodolite is placed at A and a 3 m long vertical staff is held at B. The depression angle made at reading of 2.5m marking on staff is o 6 10'.The horizontal distance between A and B is 2200 m. The height of instrument at A is 1.2 m and reduced level of point A is 880.88 m. Using curvature correction and refraction correction determine the R.L. of point B (in m).Correct answer is between '641.9,642.3'. Can you explain this answer? covers all topics & solutions for Civil Engineering (CE) 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A Theodolite is placed at A and a 3 m long vertical staff is held at B. The depression angle made at reading of 2.5m marking on staff is o 6 10'.The horizontal distance between A and B is 2200 m. The height of instrument at A is 1.2 m and reduced level of point A is 880.88 m. Using curvature correction and refraction correction determine the R.L. of point B (in m).Correct answer is between '641.9,642.3'. Can you explain this answer?.
    Solutions for A Theodolite is placed at A and a 3 m long vertical staff is held at B. The depression angle made at reading of 2.5m marking on staff is o 6 10'.The horizontal distance between A and B is 2200 m. The height of instrument at A is 1.2 m and reduced level of point A is 880.88 m. Using curvature correction and refraction correction determine the R.L. of point B (in m).Correct answer is between '641.9,642.3'. Can you explain this answer? in English & in Hindi are available as part of our courses for Civil Engineering (CE). Download more important topics, notes, lectures and mock test series for Civil Engineering (CE) Exam by signing up for free.
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