Elements of Mechanical Engineering — Winter 2022

An ideal gas is heated from 25˚Cto145˚C. The mass of gas is 2 kg. Determine

Specific heats (ii) change in internal energy, (iii) change in enthalpy. Assume R = 267 J/Kg Kand γ =1.4 for the gas.

Describe in brief the various non-ferrous metals along with their applications.

Derive the Carnot efficiency of vapour. Draw P-Vdiagram for the Carnot vapour cycle

With neat sketch explain the working of window Air Conditioner.

In an air standard Otto cycle the maximum and minimum temperatures are 1400˚Cand 15˚C. The heat supplied per kg of air is 800 kJ. Calculate the compression ratio and cycle efficiency. Also calculate the ratio of maximum to minimum pressures in the cycle

Explain with neat figure, the construction of Cochran Boiler

Classify heat engines and pumps.

Acylinder 2 stroke engine develops 30 kW at 2500 rpm. The mean effective pressure of each cylinder is 800 kPa and mechanical efficiency = 80%. Calculate brake power and mass flow rate of fuel if L/D =1.5, Brake thermal efficiency = 28% and calorific value of fuel = 44000kJ/kg.

Compare (i) Two stroke and Four stroke engine (ii) brake and clutch.

Derive the expression of work done by a single stage single acting reciprocating air compressor neglecting clearance volume. Consider adiabatic process for expansion of air.

Specify the types of centrifugal pumps and explain any one in detail.

Classify the types of couplings and with neat figure, discuss the working of any coupling of your choice.

Derive the expression for ratio of driving tensions in a flat belt drive.

Asteel drum weighing 20 kg contains 25 kg of water at 20˚C. 0.7m3 of steam at a pressure of 8 bar is passed into the drum. The temperature of water after mixing with the steam is 82˚C. find the quality of steam passed into the steel drum. Assume Cfor material of drum as 0.84 kJ/kg K. p