Biju Patnaik University of Technology 2008-2nd Sem B.Arch Architecture Mechanics-II - Question Paper
Time: 3 Hours
Answer Question No. 1 which is compulsory and any five from the rest.
The figures in the right-hand margin indicate marks.
1. Answer the following questions : 2x10
(a) Define radius of gyration.
(b) Explain shear strain.
(c) An axial load is applied on a circular section of diameter D. If the same load is applied on a hollow circular section with inner diameter 0.5 D, find the ratio of the stresses.
(e) State principle of virtual work.
(f) Efficiency of machine in an inclined plane decreases with increase in coefficient of friction. Justify.
(g) Differentiate between stable and unstable equilibrium.
(h) Explain the term center of oscillation in case of compound pendulum.
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L united we stand...
(i) Define poissions ratio.
(j) Distinguish between normal and tangential acceleration.
2. (a) A beam AB of length 3 meters is hinged at A and supported at C on a roller at a distance of 2 meters from the hinged end. Determine the reaction of the support C BEG 2001 2 Contd.
using method of virtual work. The beam carries a load of 15 kN at a distance of
1 meter from the hinged end.
5
A solid of uniform density is made of a hemisphere and a right circular cone have a common base of radius r as shown in Fig.1 Determine the largest value of height h of the cone consistent with stability of the body in the vertical position. 5
(b)
3. (a)
 |
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Fig. 1 Find the polar moment of inertia of a circular of diameter D with respect to its |
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center.
3
Find the moment of inertia about an axis parallel to x axis and passing through the center of gravity of the T section shown in Fig. 2. 7
I- 300 MM -1
30 MM
MM
Fig. 2
(a) The coefficient of friction between wet asphalt pavement and the tires of an automobile is found to have the value M-= 0.2. At what constant speed can the automobile travel around a curve of radius 250 meters without skidding if the road is level ? 4
(b) Prove that the path of a projectile motion is same as the equation of a parabola having a vertical axis. 6
5. (a) Calculate the period of small oscillation of
a circular cylindrical bar of length L and diameter D suspended from one end. 6
(b) A shaft of radius r rotates with constant angular speed w in bearings for which the coefficient of friction is n. Through what angle will it rotate after the driving torque is removed ? 4
6. (a) A steel rod 4 meters long and 20 mm
diameter is subjected to an axial tensile load of 45 kN. Find the change in length and change in diameter. Take E = 200000 N/mm2 and n= 0.25. 5
BEG 2001 5 P.T.O.
(b) Explain Mohrs circle method to obtain normal and tangential stress on a plane at an angle 0 with the major principal plane pr The plane is subjected to two unequal like principal stress p1 and p2. 5
7. The following data refer to a mild steel specimen tested in a laboratory 2x5
(i) Diameter of specimen = 25mm
(ii) Length of specimen = 320 mm
(iii) Extension under a load of 15 kN = 0.06 mm
(iv) Load at yield point =150kN
(v) Maximum load = 220 kN
(vi) Length of the specimen after failure = 380 mm
(vii) Neck diameter = 20 mm Determine
(a) Youngs modulous
(b) Stress at Yield point
(c) Ultimate stress
(d) percentage of elongation
(e) percentage reduction in area
8. (a) A small ball of weight W starts from rest at A and moves without friction along a curved path ACB as shown in Fig. 3 in a vertical plane defined by the equation
45 2
y=-2~x . Determine the reaction exerted on the ball by the path at point C. 5
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Fig. 3 (b) Explain with the neat sketch : 2.5x2 (i) Parallel axis theorem (ii) Limit of proportionality. |
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Attachment: |
| Earning: Approval pending. |
