For a constant value of coefficient of lateral friction, the value of required super elevation increases with
- AIncrease in both speed and radius of curvature
- BDecrease in both speed and radius of curvature
- CIncrease in speed and with decrease in radius of curvatureCorrect
- DDecrease in speed and with increase in radius of curvature
Solution
Concept
Superelevation required for a given speed and radius
Formula
e + f = V² / (127 R)
Step-by-step solution
1. For constant f: e = V²/(127 R) − f. 2. e increases when V increases. 3. e increases when R decreases.
Explanation
Superelevation is directly proportional to the square of the speed and inversely proportional to the radius of curvature. So it is required more at high speed and on sharp curves.
Shortcut
e ∝ V², e ∝ 1/R.
Common mistake
Thinking a larger radius needs more banking.
Correct answer: C) Increase in speed and with decrease in radius of curvature