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

Basic Mechanical Engineering June 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) Which amongst the subsequent substances, is most elastic?
(a) Brass
(b) Glass
(c) Rubber
(d) Steel
(ii) Bulk modulus is measured in terms of :
(a) N/m
(b) N/m2
(c) NM/s
(d) NS/m2
(iii) lack of toughness in a material implies :
(a) brittleness
(b) plasticity
(c) ductility
(d) softening
(B) (i) The measurement refers to :
(a) Primary signal
(b) Measured signal
(c) Output
(d) Process variable
(ii) The resolution of a system refers to :
(a) retardation of the response
(b) difference ranging from the actual and measured value of the process variable
(c) minimum value of input which is necessary to reason a detectable change from zero output
(d) smallest change of input for which there will be a change of output.
(iii) Precision is the :
(a) closeness of the instrument output to actual value of the measured volume
(b) difference ranging from measured value and actual value of the measured
(c) smallest increment in measured value that can be detected with certainty by the instrument
(d) degree of repeatability of several independent measurements of the designed input at the identical reference condition

(C) (i) The arc in the arc welding is created by :
(a) current
(b) voltage
(c) frequency
(d) constant resistance
(ii) Steam coming out of the whistle of a pressure cooker is most likely to be :
(a) wet vapor
(b) dry and saturated vapor
(c) superheated vapor
(d) very wet vapor with dryness fraction less than 0.5
(iii) The triple point of a water is :
(a) 54.35°K
(b) 13.38°K
(c) 216.50°K
(d) 273.16°K
(D) (i) The function of blow of cock in a boiler is to :
(a) blow air into the furnace
(b) remove sludge from the boiler
(c) allow flue gases to escape to the chimney
(d) drain off water resulting from partial condensation of steam
(ii) Identify the valve that prevents any water (after being pumped) reshing back from the boiler :
(a) blow of cock
(b) steam stop valve
(c) feed check valve
(d) steam trap
(iii) What is the main shaft of an engine that controls the movement of piston ?
(a) axle
(b) drive shaft
(c) crankshaft
(d) camshaft
(E) (i) Stroke of an IC engine equals
(a) half the crank radius
(b) the crank radius
(c) twice the crank radius
(d) 4 times the crank radius
(ii) The number of working strokes per minute in case 4-stroke IC engine will equal to :
(a) N/2
(b) N
(c) 2N
(d) 4N
(iii) The float in the carburetor of a petrol engine controls :
(a) flow rate of air
(b) flow rate of fuel
(c) flow rate of air-fuel mixture
(d) level of the petrol in the float chamber

2. With the help of a neat sketch discuss the construction of a boiler.

3. Draw and discuss the true and hypothetical indicator diagram for steam engine.

4. Explain the working of a 4-stroke petrol engine.

5. Define mechanical efficiency, brake thermal efficiency and indicated thermal efficiency of the internal combustion engine.

6. Explain the working of a 2-stroke petrol engine.

Earning:   Approval pending.