Question

A train is moving towards the north. At one place it turns towards north-east, here we observe that
A. The radius of the outer rail will be greater than that of the inner rail
B. The radius of the inner rail will be greater than that of the outer rail
C. The radius of curvature of one of the rails will be greater
D. The radius of curvature of the outer and inner rails will be the same

Answer 1

Hint: In order to solve this question, we will discuss the concept of radius of curvature in circular paths and using this we will discuss about the inner and outer radius of curvature of a train when it takes a turn then we will determine the correct option.

Complete step by step solution:
According to the question, we have given that initially, a train was moving straight in North direction and here remember the inner rail means the right side of the train rails whereas the outer rail means the left part of the train rails and it’s very obvious that there is a definite distance between leftmost and rightmost train rails.

Now when the train takes a turn in north-east direction means the train will turn towards right from our point of reference it means the curvature of right rails which we call inner rail will be less than that of curvature of leftmost part of train rails because outer rails are at a larger distance from the centre of the radius of curvature. When the train turns as outer rails are at some definite distance from inner rails and north-east is at the right side from the north. So, outer rails have a larger radius of curvature than the inner rail.

Hence, the correct answer is option A.

Note:It should be noted that, a train is a very long object as soon as it starts to take a turn each part of the train follows it therefore from central point of view the outer rails will always have greater radius of curvature and it will be vice-versa if train has turn left which is north-west side and it all depends upon the frame of reference.