The infinitesimal element shown in the figure (not to scale) represents the state of stress at a point in a body. What is the magnitude of the maximum principal stress (in N/mm2, in integer) at the point? ________

The cross-section of a girder is shown in the figure (not to scale). The section is symmetric about a vertical axis (Y - Y). The moment of inertia of the section about the horizontal axis (X - X) passing through the centroid is _______ cm4 (round off to nearest integer). 

Consider the following three structures : 

Structure I : Beam with hinge support at A, roller at C, guided roller at E, and internal hinges at B and D

Structure II : Pin-jointed truss, with hinge support at A, and rollers at B and D

Structure III : Pin-jointed truss, with hinge support at A and roller at C

Which of the following statements is/are TRUE?

Consider the pin-jointed truss shown in the figure (not to scale). All members have the same axial rigidity, AE. Members QR, RS, and ST have the same length L. Angles QBT, RCT, SDT are all 90°. Angles BQT, CRT, DST are all 30°. The joint T carries a vertical load P. The vertical deflection of joint T is k$\rm \frac{PL}{AE}$. What is the value of k?