#### Strenght of Materials

21

The longitudinal stress in a riveted cylindrical shell of diameter (d), thickness (t) and subjected to an internal pressure (p) is

A. (pd)/(tn)
B. (pd)/(2tn)
C. (pd)/(4tn)
D. (pd)/(8tn)

22
When the retained material is subjected to some superimposed or surcharged load, the total horizontal pressure due to surcharged load is (where p = Intensity of the supercharged load)
A. p xx (1 - sin phi)/(1 + sin phi)
B. p xx (1 + sin phi)/(1 - sin phi)
C. p xx (1 - cos phi)/(1 + cos phi)
D. p xx (1 +cos phi)/(1 - cos phi)

23

When a body is subjected to a direct tensile stress (sigma) in one plane, then normal stress on an oblique section of the body inclined at an angle theta to the normal of the section is

A. sigma cos theta
B. sigma cos^2 theta
C. sigma sin theta
D. sigma sin^2theta

24

The change in length due to a tensile or compressive force acting on a body is given by (where P = Tensile or compressive force acting on the body, l = Original length of the body, A = Cross-sectional area of the body, and E = Young's modulus for the material of the body)

A. (P.l.A)/(E)
B. (P.l)/(A.E)
C. (E)/(P.l..A)
D. (A.E)/(P.l)

25
In a leaf spring, the deflection at the centre is

A. (wl^3)/(8Enbt^3)
B. (wl^3)/(4Enbt^3)
C. (3wl^3)/(8Enbt^3)
D. (wl^3)/(2Enbt^3)