Mechanical Engineering Answers

 Find the minimum number of teeth on gear wheel to avoid undercutting when the 

addendum for stub teeth is 0.84 module and pressure angle is 200

, if gear ratio is 

3:1

In a crank and slotted lever mechanism, the length of crank is 560 mm and the

ratio of time of working stroke to return stroke is 2.8. Determine (a) distance

between the fixed centres, and (b) the length of the slotted lever, if length of

stroke is 250 mm.

0.05 m^3 of gas at 6.9 bar expands reversibly in a Cylinder behind a piston according to a PV^ prime prime =C until the Volume is 0.08 m Calculate the work done by the gas and Sketch the process 0.05m ^ 3 of law on p-v diagram.

A fluid at 6.15 bar is expanded reversibly according to law PV = constant to a pressure of 2.15 bar until it has a specific volume of 0.22 m³/kg. It is then cooled reversibly at a constant pressure, then is cooled at constant volume until the pressure is 0.82 bar; and is then allowed to compress reversibly according to a law PVn = constant back to the initial conditions. The work done in the constant pressure is 0.625 kJ, and the mass of fluid present is 0.32 kg. Calculate the value of n in the fourth process, the net work of the cycle and sketch the cycle on a P-V diagram

Explain tensile testing for ductile and brittle materials. [14]

2. What is Cast Iron? Explain different types of CI with industrial uses. [7]

3. What is hardness? How do you measure it? [7]

4. Classify engineering materials. [7]

5. Explain following properties [7]

i. Strength

ii. Fatigue

iii. Ductility

iv. Toughness

6. A hollow right circular cylinder is made of certain material and has an outside

diameter of 75mm and an inside diameter of 60mm. The cylinder measures 600

mm in length and is subjected to axial compressive load of 50kN. Determine

i. Stress

ii. Deformation

iii. Material type

Take the modulus of elasticity of the material to be 100 GPa. [8]

0.2 m3 of an ideal gas at a pressure of 2000kpa and 327 C is expanded isothermally to initial volume it is then cooled to 25 C at constant volume and then compresses back polytropically toits intial state.Determine net work done

Explain different parts of a characteristic stress-strain diagram of steel.

Explain key assumptions in the theory of simple stress.

The two cylindrical rod segments are fixed to the rigid walls such that there is a gap of 0.01in between

them when T1 = 60^oF. Determine the larger temperature T2 required in order to just close the gap

without producing stresses in the rods? Each rod has a diameter of 1.25in. Take (alpha)al = 13 x 10^-6 in/in ^oF,

Eal = 104 ksi, (Alpha)cu = 9.4 x 10^-6 in/in ^oF, Ecu = 15 x 10³ ksi.

Steam flows through a turbine at the rate of 50 kg/min with ΔKE= 0 and Q = 0. At entry, its pressure is 1200kPaa, its specific volume = 0.2 m3 /kg and its internal energy is 1230 KJ/kg. At exit, its pressure is 5.6 kPaa, its specific volume is 20.5 m3 /kg and its internal energy is 902 KJ/kg. What horsepower is developed?, (b) The same as (a) except that the heat loss from the turbine is 10 KJ/kg of steam