UPSC Civil Service Exam Questions - Engineering

Q1:

A simply supported beam of span L carries a concentrated load W at its mid-span. If the width 'b' of the beam is constant throughout the span, then, when the permissible bending stress is 'f', the beam's mid-span depth will be

A 3WL/2bf

B
3WL/2bf

C 6WL/bf

D
6WL/bf

ANS:B -

3WL/2bf

Ans b.

M= f * z.

wl/4=f*bd^2/6.
Then d =root of (3wl/2bf).