Question

A cantilever beam AB of span 3 m is fixed at A and free at B is subjected to a concentrated load of 50 kN acting at a distance of 2 m from the fixed end. The maximum bending moment in the beam is

• A. 50 kNm at A
• B. 100 kNm at A
• C. 150 kNm at A
• D. 100 kNm under the load.

Hint:

For any cantilever beam, the maximum bending moment and maximum shear force will always occur at the fixed support.
Simply calculate the total moment caused by all loads about the fixed support to find the maximum bending moment.

Answer 1

The Correct Option is B

Step 1: Understanding the Question:
Cantilever 3m, point load 50kN at 2m from fixed end. Find max BM.

Step 2: Key Concept (Alternate):
In cantilever, max BM always at fixed support. BM at support = force × distance from support.

Step 3: Detailed Explanation:
Fixed end A, load at 2m from A. M_A = 50×2 = 100kNm (hogging). Between load and free end, BM=0. From load to support, BM varies linearly from 0 to 100kNm.

Step 4: Final Answer:
Maximum BM is 100 kNm at fixed end.