APPSC Inspector of Factories Mechanical Paper 2008

Andhra Pradesh PSC Inspector of Factories Mechanical Paper 2008

An oil engine working on ideal diesel cycle has 20 cm bore and 30 cm stroke and the clearance volume is 420 cubic cm. The fuel suply is 50% of the stroke. If the fuel supply is delayed from 5% to 8%. Find the percentage change in thermal efficiency
(a) 64.7%
(b) 7.75%
(c) 52.4%
(d) 58.0%

The efficiency of Carnot cycle may be highest
(a) By increasing the source temperature
(b) By increasing sink-temperature
(c) By increasing source temperature and decreasing sink temperature simultaneously
(d) By decreasing source temperature and increasing sink temperature simultaneously

The examples for intensive properties are
(a) Pressure, temperature, and density
(b) Volume, mass and total energy
(c) Temperture, mass and volume
(d) Pressure, mass and total energy

The flame travel in SI engines is very slow initially due to
(a) Low transposition rate and low turbulence
(b) spark plug being located very close to the cylinder wall
(c) low turbulence and low heat liberation
(d) fraction of unburned mass which is a function of crank angle

An engineer claims to have developed an heat engine, which absorbs 100 kW of heat from a thermal reservior at 1000 K, 80 kW of heat from another thermal reservoir at 1600 K, produces 130 kW of work output, and rejects heat to the thermal reservoir at 500 K. Which of the following statement(s) is/ are correct?
(a) This heat engine violates second law of thermodynamics
(b) The amount of heat rejected to the sink is 50 kW
(c) Cyclic integral of dQ/T is 0.05
(d) All of the above

A simple carburettor has a venturithroat diameter of 22 mm and the coefficient of flow is 0.82. The fuel orifice has a diameter of 1.2 mm and the coefficient of fuel flow is 0.70. The petrol surface is 4 mm below the throat. Taking nozzle tip into account, the air/fuel ratio for a pressure drop of 0.075 bar is
(a) 12.75
(b) 15.78
(c) 7.0
(d) 1.6155

A heat engine is suplied with heat from a source at 1000 K and rejects heat to a sink at 300 K and this engine is operating with a thermal efficiency of 30%. The second law efficiency of this heat engine is
(a) 60%
(b) 43%
(c) 30%
(d) 70%

The ‘change in entropy’ of a reversible-adiabatic turbine is
(a) zero
(b) greater than one
(c) one
(d) negative

What is the purpose of a particulate trap?
(a) Filter the impurities, oxidize them and cleans the filter
(b) It is a three way catalyst which removes all the three pollutants simultaneously
(c) It is a single converter used to oxidize carbon monoxide and hydrocarbons
(d) It is a thin steel liner in a thermal reactor to minimize heat losses by thermally isolating the core

The concepts useful to measure the ‘quality of energy’ is
(a) Energy
(b) Irreversibility
(c) Reversible work
(d) All of the above