Rajiv Gandhi Proudyogiki Vishwavidyalaya 2007 B.E Mechanical Engineering Basic uary/raury - Question Paper

Basic Mechanical Engineering January/February 2007 ques. Paper

1. Attempt any 2 objective ques. every from A to E. (Total no. of 10 ques. are to be attempted):
(A) (i) The property of material which enables it to draw out into wire is:
(a) Toughness
(b) Hardness
(c) Ductility
(d) None of the above
(ii) The pattern, which is used to produce circular castings:
(a) Skeleton trend
(b) Segmental trend
(c) Loose piece trend
(d) None of the above
(iii) The permeability of a molding sand indicates its:
(a) Flow ability
(b) Porosity
(c) Collapsible
(d) None of the above
(B) (i) In the measuring instrument, the ratio ranging from the displacement of the pointer in scale division and the corresponding change in the measured value is called:
(a) Accuracy
(b) Linearity
(c) Sensitivity
(d) Range
(ii) For holding symmetrical round or hexagonal shaped workpiece in lathe machine, the kind of check used is:
(a) Four jaw chuck
(b) Three jaw chuck
(c) Magnetic chuck
(d) None of the above
(iii) The operation of finishing and sizing a hole is called:
(a) Reaming
(b) Drilling
(c) Boring
(d) None of the above
(C) (i) Fusion welding is a pressure welding
(a) True
(b) False
(ii) Cold working is used for non-ferrous sheet metals.
(a) True
(b) False
(iii) Only coated electrodes can be used in O.C. arc welding.
(a) True
(b) False
(D) (i) Bab cox and Wilcox boiler is a fire tube boiler
(a) True
(b) False
(ii) Heat addition in a constant temperature is latent heat.
(a) True
(b) False
(iii) Mechanical efficiency is the ratio of brake power to indicate power.
(a) True
(b) False
(E) (i) 4-stroke engine exhaust more pollution than 2-stroke engines.
(a) True
(b) False
(ii) Flywheel is used to make crankshaft rotation more uniform.
(a) True
(b) False
(iii)
In 2-stroke engine, power stroke takes place after every 2 revolutions of crankshaft.
(a) True
(b) False
2. (a) Differentiate ranging from elastic limit and proportional limit.
(b) Discuss the different trend making allowances.

OR
(a) Differentiate ranging from ductility and malleability.
(b) Discuss the derived properties of molding sand.

3. (a) What is the function of form gauges?
(b) What do you understand by cutting tool nomenclature? Sketch and tag tool angles/tool nomenclature.

OR
(a) What is the function of snap gauges?
(b) What are the main parts and their functions of a lathe machine? How a lathe is specified?

4. (a) What do you mean by weld ability? elaborate the factors on which it depends?
(b) Discuss and compare ranging from AC and DC Arc welding.

OR
(a) What is the main difference ranging from MIG and TIG Arc welding?
(b) What are the equipments used in oxy-acetylene welding? Also explain the different flame zones.

5. (a) What is the difference ranging from boiler mountings and accessories?
(b) Calculate the internal energy per kg of superheated steam at a pressure of 10 bar and a temperature of 300°C. obtain the change of internal energy if this steam expands to 1.4 bar and dryness fraction 0.8.

OR
(a) Define the subsequent :
(i) Equivalent evaporation
(ii) Boiler efficiency
(b) Two boiler 1 with superheater and other without super heater are delivering equal volumes of steam into a common main. The pressure in the boilers and main is 15 bar. The temperature of the steam from a boiler with super heater is 300°C and temperature of the steam in the main is 200°C. Determine the quality of steam supplied by the other boiler.

6. (a) Differentiate ranging from a flywheel and a governor.
(b) Compare the power output for Diesel and Otto engine from the subsequent available data:
Maximum temperature = 1227°C
Exhaust temperature = 477°C
Ambient condition - atmospheric pressure = one bar
Temperature = 27°C
Air consumption = 477°C
Assume : Cp = 1.005 kJ/kg k, Cv = 0.718 kJ/kg k, y = 1.4

OR
(a) Draw the Otto cycle on P-V and T-S diagram.
(b)
An Otto cycle takes in air at 300°K. The ratio of maximum to minimum temperature is 6. obtain out the optimum compression ratio for the maximum work output of the cycle.

Earning:   Approval pending.