Question 81. An ideal gas of mass m and temperature T1 undergoes a reversible isothermal process from an initial pressure P1 to final pressure P2. The heat loss during the process is Q. The entropy change ∆S of the gas is

Question 82. Oil flows through a 200 mm diameter horizontal cast iron pipe (friction factor, f = 0.0225) of
length 500 m. The volumetric flow rate is 0.2 m3/s. The head loss (in m) due to friction is (assume
g = 9.81 m/s2)

Question 83. Which one of the following configurations has the highest fin effectiveness?

Question 84. In a shaping process, the number of double strokes per minute is 30 and the quick return ratio is 0.6.
If the length of the stroke is 250 mm, the average cutting velocity in m/min is

Question 85. A milk vendor incurs an overstocking cost of Rs. 2 per litre and a shortage cost of Rs. 0.5 per litre.
The demand is uniformly distributed between 1 litre and 6 litres. Using the Newsvendor Model, the
maximum quantity of milk in litre(s) the vendor should order is

Question 86. On an average, there are 30 customers in a queue. If the arrival rate of customers into the system is
16 customers per hour and on average 32 customers leave the system per hour, then the average
number of customers in the system is

Question 87. For a linear programming problem, the set of constraints x + y ≤ 2, 3x + 5y ≥ 15, x ≥ 0 and y ≥ 0 leads to

Question 88. The specification limits for the weight of a product are 13.1 kg and 15 kg. If the process has a
variance of weight 0.05 kg2, then the process capability index is

Question 89. In orthogonal turning of a bar of 100 mm diameter with a feed of 0.25 mm/rev, depth of cut of 4 mm and
cutting velocity of 90 m/min, it is observed that the main (tangential) cutting force is perpendicular to the
friction force acting at the chip-tool interface. The main (tangential) cutting force is 1500 N. The normal force acting at the chip-tool interface in N is

Question 90. Were you a bird, you ___________________ in the sky.