# Civil Engineering - UPSC Civil Service Exam Questions - Discussion

20.

The plastic section modulus of a rectangular section of width 100 mm and depth 12 mm is

 [A]. 1000 mm3 [B]. 1800 mm3 [C]. 2400 mm3 [D]. 3600 mm3

Explanation:

No answer description available for this question.

 Barqat Sheikh said: (Feb 25, 2015) Plastic section modulus = b*h^2/4. = 3600 mm^3.

 Hemanth Kumar said: (Nov 16, 2016) Z = bd^2/6 = 2400mm^3.

 Kanu said: (Apr 7, 2017) Here the section is rectangular. Z= (bd^2)/4 is right If in case there is a circular section then section modulus will be; Z = (bd^2)/6.

 Deepak Dalal And Ritu Dalal said: (Apr 28, 2017) Section modulus = moment of inertia of the area / maximum distance of any point from the axis. Moment of inertia for rectangular section = bh^3/12. Maximum distance of any point from the axis = h/2. So, section modulus for rectangular section = bh^2/6. And the correct answer from above from is 2400.

 Naveen Kallan said: (Sep 14, 2017) Shape factor= 1.5 for rectangular section S.F = Zp/Ze Ze = bd^2/6 Zp = 3600 mm^3.

 Aatif said: (Jan 15, 2018) Answer should be 2400. Section modulus for rect section- bd^2/6.

 Darshan said: (Jan 18, 2018) Plastic modulus and elastic modulus are different. shape factor comes into picture here; so 2400 *1.5 = 3600. shape factor is 1.5 for rectangular section.

 Subha Annadurai said: (Mar 12, 2018) How to find plastic section modules & elastic section modules for rectangle?

 Subha Annadurai said: (Mar 12, 2018) For rectangle, Plastic section modules = bd^2/4, Elastic section modules = bd^2/6, Shape factor = 1.5.

 Ravi Rajput said: (Oct 10, 2018) How to calculate plastic section modulus? Please explain.

 Anil Kumar said: (Nov 24, 2019) (Zp=Ac x yc+At x yt). Ac = area of compression zone. At = area of tension zone. Yc &yt are the C.G of the both zones. So the answer is zp = 600x300+600x300. =3600.