# Civil Engineering - Surveying - Discussion

### Discussion :: Surveying - Section 1 (Q.No.42)

42.

The slope correction for a length of 30 m along a gradient of 1 in 20, is

 [A]. 3.75 cm [B]. 0.375 cm [C]. 37.5 cm [D]. 2.75 cm.

Explanation:

No answer description available for this question.

 Sandeep said: (Aug 28, 2013) (1.5)2 / 2x3000 = 3.75 cm. Note: Length 30 m, gradient 1/20 ; h= 1.5. Equation : h2/2l.

 Hitesh Kumar said: (Jan 17, 2014) Slope correction= h/2*2l.

 Priya said: (Oct 31, 2014) Can any one explain this properly?

 Dash said: (Dec 18, 2014) What is Gradient?

 Ahishek said: (Dec 29, 2014) How h = 1.5?

 Anil Soni said: (Jan 14, 2015) For 20 m, h = 1 m. So for 30 m, h = 1.5 m.

 Pranab said: (Mar 4, 2015) h = 1.5 m & l = 30 m. So that = h2/2l = (1.5)2/2*30 = 0.0375 cm.

 Prashant said: (Mar 25, 2015) (H2/2L)+(H4/8L3) as gradient is 1 in 20. i.e For 20 m, h = 1 m. So for 30 m, h = 1.5 m which is less than 3 m. Therefore second term of equation should be neglected. Answer is (1.5)2/2x3000 = 3.75 cm.

 Engr Attaullah Khan Tareen said: (May 6, 2015) For 20 m, h = 1 m. So for 30 m, h = 1.5 m. So that = h^2/2l = (1.5) 2/2*30 = 0.0375 m. 1 m = 100 cm so 0.0375*100 = 3.75 cm.

 Maheshkumar said: (Jun 3, 2015) In 1 in 20 means, 20m = 1m. So total 30m length = 1.5m. In Gradient 1 in 20 Means. Imagine Triangle, length-30m & Height-1.5m. Use Pythagoras theorem. X2 = 302+1.52. X = 30.0375m. Change length = 30.0375-30. = 0.0375m. = 3.75cm.

 Kanhu said: (Jul 24, 2015) Slope correction for a sloping ground = h^2/2l. Where h = height. l = length of the ground.

 Ali said: (Apr 8, 2016) We know for 30 m length, h = 1.5 And given gradient is 1 in 20 i.e 1/20 So, the equation of slope correction is, = h^2 / 2l = 1.5^2 / 2*30 m = 2.25 / 60m = 0.0375 m or 3.75 cm

 Swamy said: (Aug 31, 2016) Hi, friends all give the good explanations. Thank you.

 Hima Bindu said: (Sep 23, 2016) How h =1.5?

 Md Faisal said: (Nov 3, 2016) In ABC triangle, AC = l = 30m. Slope = 1 : 20. 1 in20 so in 30 = (1/20) * 30 = 1.5 Therefore BC = 1.5m. And AB extends to BB'. And meet to points A as arc & B as a straight line. Here BB'= correction of line, = AC - AB. AB = (30^2 - 1.5^2)^1/2 = 29.962m. BB' = 30 - 29.962 = 0.0375m or 3.75cm.

 Baloch said: (Nov 28, 2016) Slope correction = h^2 / 2l. h = 20/30 = 1.5. l = length. By submitting the value you will get the answer.

 Nawa Raj Budha said: (Dec 12, 2016) Good explanations friends. Thank you.

 Sanjukta said: (Dec 17, 2016) Thank you for the explanation friends.

 Bhupendra Murariya said: (Feb 3, 2017) Not understanding, Please give the correct explanation for this question.

 Sunny Thakur said: (Mar 27, 2017) Thanks for the explanation friends.

 Harsh Rathod said: (Jun 3, 2017) Thank you all for your explanation.

 Swethakondisetty said: (Jun 27, 2017) Slope correction =h^2/2l.

 Juhi said: (Jul 13, 2017) Thank you all for your explanations.

 Sathya said: (Jul 16, 2017) 30 m length, h = 1.5. Given gradient is 1 in 20 i.e 1/20. The equation of slope correction is, = h^2/2l. = 1.5^2 / 2*30 m, = 2.25 / 60m, = 0.0375 m or 3.75 cm.

 Vijay Bhaskar said: (Dec 5, 2017) How h= 1.5?

 Avijit Patra said: (Jan 16, 2018) Here, l= 30 m. Gradient= 1 in 20, i.e h= 30/20= 1.5 We know, slope correction (Ch)= - h^2/2l = - (1.5)^2/(2*30) m. = -3.75 cm.

 Asad Ali Chandia said: (Jan 22, 2018) Slop correction Formula = h^2/2*L. h = 30*(1/20) = 1.5 Hence, correction = 3.375 cm.

 Abhinandan Kumar said: (Mar 13, 2018) 1 in 20 means 0.05, So in 30 means 0.05*30=1.5(which is h), And we know the formula for a lope correction =h^2/2L, So 1.5^2/2*30=0.0375m and in cm. We get 3.75 m.

 Rasheedrash79 said: (Mar 28, 2018) How are they getting 1.5*2=2.25? Please explain.

 Sameer Sopori said: (May 2, 2018) h^2/2L. h= 1.5 (because of 1:20, 1/20 * 30 = 1.5), h= 2.25/60, h= 0.375m, h= 0.375 * 100, h= 3.75cm.

 Samadhan said: (May 14, 2018) Slope means= just an inclined line. always 1st value indicates vertical distance & 2nd indicates horizontal distance...So h=1.5 how? see h=(V/H.), where V=vertical distance H=Horizontal distance. So, first Given(1 V/20 H)=(1/20)=0.05 this value in meter (we calculated slope length for 1 meter but given(30m), h=height between two endpoints of the slope. We have to calculate for 30 m) so just multiply =0.05*30=1.5 m Now, don't use (h^2/2L) formula it's approx. By using the formula, we get 0.03752346684 in meter now in option all value in cm. So just convert in cm = 3.75234668427 answer. h=height between two endpoints of the slope, hope this concept is clear.

 Mamatamayee said: (May 19, 2018) Thanks for the explanation.

 Samadhan said: (May 20, 2018) The exact formula is = (L- √(L^2-h^2)) Now in words Where L=length and h =meaning is same as above, L=30m And h=1.5m..

 Aditya Singh said: (May 28, 2018) Let me clearly explain this for those who are confused. The formula for slope correction is; C=h^2/2L. Now since grade is given is 1 in 20. That means for 20 m horizontal movement there will be a movement of 1m vertical..therefore accordingly for 30 m it will30/20 =1.5m. Now, put this into the formula and you will get 3.75 as answer.

 Kiran said: (Jun 12, 2018) Thank you all for explaining the solution.

 Gulshan Kumar said: (Jun 27, 2018) But 30 M is along the gradient, not horizontal distance. So, the value of h won't be exactly 1.5 M.

 Shubhajit Chakrabarty said: (Sep 9, 2018) Let me clearly explain, tanθ = height/ base. => tanθ = 1/20, =>θ = 2.86. Now actual slop correction = l(1-cosθ). => 30(1-cos2.86) = 0.0373m. => 3.73 cm.

 Manoj said: (Nov 5, 2018) Here h= 1.5, it is not correct because here 30 m is hypotenuse (i.e. equals to L , which is also used in slope correction formula ) but why use as a base or horizontal for finding h? Please explain me.

 Manoj said: (Nov 5, 2018) By using of similarity of the triangle. H = 30÷401 and putting into slope correction formula.

 Omgir said: (Nov 9, 2018) Helpful explanation. Thank you all.

 Don Chandu said: (Jun 1, 2019) For 20 m vertical 1m. For 30m h = 30/20 = 1.5. Slope correction = h^2/2l = 1.5^2/(2 * 30) = 0.0375m = 3.75cm.

 Ritesh Kumar Singh said: (Jul 15, 2019) Thanks for the explanation @Shubhajit Chakrabarty.

 Sindhu said: (Aug 8, 2019) If 30m replace 60m then h=?

 Sathya said: (Aug 8, 2019) @Sindhu. It is 0.075.

 Karn Chaurasiya said: (Sep 10, 2019) 150/ n^2 because 30 metre chain used and now slope current is 150/ 20^2 = 150 ÷ 400 = 0.375 m or 3. 75 cm.

 Charan Singh Majhi said: (Nov 8, 2019) Slope correction = h^2/2l = 1.5^2/2*30 = 0.0375mtr = 3.75cm.

 Ankit said: (Jan 12, 2020) Slope correction is negative or positive? Give details about it.

 Adarsh Krishna said: (Feb 19, 2020) h^2/2l = 1.5*1.5/(2*30) = .0375m its change cm. = 3.75cm

 Adarsh said: (Feb 19, 2020) Slope correction is always negative.

 Lav Kumar Yadav said: (Feb 21, 2020) Slope correction =h^2/2L. So, 1:20. 20m=1m. 1m=1/20m. 30m=1/20*30=1.5. H= 1.5. (1.5) ^2/2*30=0.0375m. = 3.75 cm Answer.