Civil Engineering MCQJE Level Civil Engineering

A hollow shaft (D_o=100mm, D_i=50mm) vs solid shaft (D=100mm), same material and torque. Hollow shaft weight saving:

Strength of MaterialsTorsionMEDIUM

Choose the correct answer

A

75%

B

25%

C

50%

D

12.5%

Correct Answer

B. 25%

Why is this the answer?

Weight ∝ cross-sectional area. Solid: π×100²/4. Hollow: π(100²−50²)/4 = π×7500/4. Saving = (100²−(100²−50²))/100² = 2500/10000 = 25%.

Related Strength of Materials MCQs

More solved Strength of Materials questions for AE/JE Civil Engineering exams.

View all Strength of Materials MCQs →

Practice more Civil Engineering questions

This MCQ belongs to Magic Mock Test Series — RRB JE Civil (CBT-2). Full tests include timed attempts, rank comparison and subject-wise analysis.

Create Free Account