BT-203 (GS) – Basic Mechanical Engineering

Explain the methods to measure the hardness of materials.

A flat plate of area 1.5 × 10⁶ mm² is pulled with a speed of 0.4 m/s relative to another plate located at a distance of 0.15 mm from it. Find the force and power required to maintain this speed, if the fluid separating them is having viscosity as 1 poise. [1 poise = 0.1 N s/m²]

Classify engineering materials. What do you mean by alloys? Write some applications of alloys.

A rod 200 cm long and of diameter 3.0 cm is subjected to an axial pull of 30 kN. If the Young's modulus of the material of the road is 2 × 10⁵ N/mm², determine:

i) Stress,

ii) Strain,

iii) Elongation of the road.

With a neat diagram explain the main parts of a lathe machine. Explain any two operations performed on a lathe machine.

During a trial operation of a boiler 1630 kg of coal were consumed in 24 hrs. and 13000 kg of water evaporated. The mean steam pressure was 7 kgf/cm² and condition dry saturated. The fuel contained 3 percent moisture and 4 percent ash and had a calorific value of 7200 kcal/kg. The feed water temperature was 35°C. Determine:

i) The boiler efficiency,

ii) The equivalent evaporation per kg of dry coal,

iii) The equivalent evaporation per kg of combustibles.

Explain the working of a manometer for pressure measurement. Also relate absolute pressure, gauge pressure and vacuum pressure.

Explain the measurement process using vernier calliper with neat sketch.

Define Viscosity. What is the importance of viscosity while selecting fluids in various engineering applications?

Discuss briefly the differences between externally fired and internally fired-steam generators. Also discuss the application of each type of steam generators.

Explain working principle of hydraulic turbines (Pelton wheel) with neat sketch.

Derive an expression for efficiency of Otto cycle with neat sketches of PV and TS diagrams.

State the Zeroth Law of thermodynamics. How is mercury in thermometer able to find the temperature of a body using the Zeroth law of thermodynamics?

Explain the working of four stroke diesel engine with neat sketch.

Write Short notes on (Any two): a) Welding defects b) Dial gauge c) Sine bar d) Thermodynamic properties