GATE-MECHANICAL ENGG.[A story]

GATE 2016 topper reveals success mantra to crack the exam: Read to know Khantesh Mohanbhai Agrawal's inspirational story 
INDIATODAY.IN NEW DELHI, APRIL 5, 2016


Q. Did you take any coaching classes? Are they important for preparations?
Khantesh: Yes, I did enroll for GATEFORUM Distance Learning Program (DLP) and EII online Test Series, but I hardly used any of them since the major chunk of my preparation was self-study, solving problems from www.unitoperation.com and discussing doubts with friends. Joining coaching classes is a subjective question and varies from person to person and his prior knowledge in subjects. If you have studied decently during your graduation, there is not much need of coaching, although a test series may help you to manage time. However, there are no good test series available in Chemical Engineering.
Read the whole story from Nptel website link(Click here).

INDUSTRIAL ENGINEERING: Quick recap(questions)

1. If the duration of activity f alone is changed from 9 to 10 days, then the
(A) critical path remains the same and the total duration to complete the project changes to 19 days.
(B) critical path and the total duration to complete the project remains the same.
(C) critical path changes but the total duration to complete the project remains the same.
(D) critical path changes and the total duration to complete the project changes to 17 days


2.For the standard transportation linear programme with m source and n destinations and total supply equaling total demand, an optimal solution (lowest cost) with the smallest number of non-zero xij values (amounts from source i to destination j ) is desired. The best upper bound for this number is
(A) mn                                                              (B) 2(m + n)
(C) m + n                                                          (D) m + n - 1


3.A company produces two types of toys : P and Q. Production time of Q is twice that of P and the company has a maximum of 2000 time units per day. The supply of raw material is just sufficient to produce 1500 toys (of any type) per day. Toy type Q requires an electric switch which is available @ 600 pieces per day only. The company makes a profit of Rs. 3 and Rs. 5 on type P and Q respectively. For maximization of profits, the daily production quantities of P and Q toys should respectively be
(A) 1000, 500                                                    (B) 500, 1000
(C) 800, 600                                                      (D) 1000, 1000



Answer:
1. (A)
2. (D)
3. (A)

Heat Transfer:Quick recap(questions)

  • For the same inlet and outlet temperatures of hot and cold fluids, the Log mean Temperature Difference (LMTD) is
          (A) greater for parallel flow heat exchanger than for counter flow heat
          exchanger
          (B) greater for counter flow heat exchanger than for parallel flow heat
          exchanger
          (C) same for both parallel and counter flow heat exchangers
          (D) dependent on the properties of the fluids.

  • In a counter flow heat exchanger, for the hot fluid the heat capacity = 2 kJ/kgK, mass flow rate= 5 kg/s, inlet temperature = 150cC, outlet temperature = 100cC. For the cold fluid, heat capacity = 4 kJ/kgK, mass flow rate = 10 kg/s, inlet temperature = 20cC. Neglecting heat transfer to the surroundings, the outlet temperature of the cold fluid in cC is                            (A) 7.5
    (B) 32.5
    (C) 45.5
    (D) 70.0
  •  The logarithmic mean temperature difference (LMTD) of a counter flow heat exchanger is 20cC. The cold fluid enters at 20cC and the hot fluid enters at 100cC. Mass flow rate of the cold fluid is twice that of the hot fluid. Specific heat at constant pressure of the hot fluid is twice that of the cold fluid. The exit temperature of the cold fluid
    (A) is 40cC
    (B) is 60cC
    (C) is 80cC
    (D) cannot be determined




Answers:
1. (C)
2. (B)
3. (C)

Machine design: Quick recap(questions)


  • A butt weld joint is developed on steel plates having yield and ultimate tensile strength of 500 MPa and 700 MPa, respectively. The thickness of the plates is 8 mm and width is 20 mm. Improper selection of welding parameters caused an undercut of 3 mm depth along the weld. The maximum transverse tensile load (in kN) carrying capacity of the developed weld joint is?
  • A metric thread of pitch 2 rnrn and thread angle 60 degree is inspected for its pitch diameter using 3 wire method. The diameter of the best size wire in mm  is 
           (a) 0.866  (b) 1.000  (c)1.154  (d)2.000






Answers:
1.70KN
2. (c)


Thermodynamics: Quick recap(questions)


1. The definition of 1 K as per the internationally accepted temperature scale is
(a) 1/100th the difference between normal boiling point and normal freezing point of water
(b) 1/273.15th the normal freezing point of water
(c) 100 times the difference between the triple point of water and the normal freezing point ‘ of water
(d) 1/273.16‘“ of the triple point of water

2.The volume and temperature of air (assumed to be an ideal gas) in a closed vessel is 2.87 m3 and 300 K. respectively. The gauge pressure indicated by a manometer fitted to the wall of the vessel is 0.5 bar. If the gas constant of air is R = 287 J/kgK and the atmospheric pressure is 1 bar, the mass of air (in kg) in the vessel is
(a) 1.67
(b) 3.33
(C) 5-00
(d) 6.66

3.Air expands steadily through a turbine from 6 bar, 800 to 1 bar, 520 K. During the expansion, heat transfer from air to the surroundings at 300 K is 10 kj/kg air. Neglect the changes in kinetic and potential energies and evaluate the irreversibiiity per kg air. Assume air to behave as an ideai gas with Cp=1.0 kj/kgk and R=0.3/KgK




Ans:
1.(d)
2.(c)
3. 42.03 kj/kg