Question1: (Mechanics of Materials)
Three vertical wires A, B and C are suspended from rigid supports as shown. A rigid horizontal cross bar is connected at their lower ends, it is supporting a load of 20kN. The bar is horizontal before and after the application of load. Determine the load supported, stresses induced and the deformations of all the bars. Also workout the position of the load on the horizontal bar.
Question2: (Mechanics of Materials)
A rectangular block is 25cm long, 7.5cm wide and 2.5cm thick is loaded with a 250kN tensileload along the axis of the member. A compressive force of 2000kN acts on the face 25cm x 7.5cm and a tensile force of 400kN acts on the face 25cm x 2.5cm.
If μ = 0.3 and E = 200GPa determine the change in length, change in width and change in thickness of the bar.
What must be the load that should be applied in place of 2000kN so that the change in volume of the bar is zero
Question3: (Mechanics of Materials)
A stepped bar having circular sections of diameter 1.5D and D is shown. If ρ and E are the density and Young's modulus of elasticity respectively, find the extension of the bar due to its own weight.
Question 4: (Heat transfer)
Derive the following expression for loss of heat from a lagged pipe per square meter of metal surface per degree temperature difference between the metal and lagging surface.
Where K is thermal conductivity of lagging material, r and R are the radii of metal and lagging surface.
Neglect thermal resistance due to metal surface.
Question5: (Heat transfer)
An electrical resistance of mattress type is inserted in between two slabs of different materials on a panel heater. On one side, the material has a thermal conductivity of 0.174W/m-K and 10mm thick. On the other side of the heater the material has a thermal conductivity of 0.05W/m-K and 25mm thick. The convection heat transfer co-efficient from the thinner and thicker slabs are 23.26 W/m-K and 11.63 W/m-K. The temperature of the surrounding air on both the sides is 150 C. If the energy dissipation for each square meter of the mattress is 5kW,neglecting edge effects, find:
(i) The surface temperatures of the slabs,
(ii) The temperature of the mattress assuming it to be the same as the inner surface of the slabs.
Question6: (Engg Drawing)
A square prism of 30mm side of base and height 60mm rests with one of its edges of the base on HP such that the axis is inclined at 400 to HP and 300 to VP. Draw the top and front views of the prism