Mechanical Engineering Answers

NO. 5. A rigid airport pavement is to be designed for the following data.
– Dual tandem aircraft (gross weight = 300,000 lbs)
– annual equivalent departures = 13000
– Subgrade k = 150 pci with poor drainage, frost penetration = 18 in.
– Primary runway, 100% frost protection
– Subgrade soil is CL
– Concrete flexural strength = 650 psi

10. Probabilistic time for completion of any activity can be found out from

1. pessimistic time

2. optimistic time

3. most likely time

4. all of these

9. Gantt chart is used for

1. inventory control

2. material handling

3. production schedule

4. machine repair schedules

8. The chart which gives an estimate about the amount of materials handling between various work stations is known as

1. operation chart

2. flow chart

3. process chart

4. travel chart

7. Read the following three statements:

a) Service industries deal with tangible products only.

b) Unlike a product, a service can be kept in stock (inventory).

c) Compared with service industries, manufacturing industries usually require large capital outlays.

Which of the above statements is/are correct?




[1] b and c

[2] a and c

[3] a and b

[4] a, b and c

[5] None of the above options (1, 2, 3, or 4) is correct

6. Read the following three statements:

a) During the operational transformation process, equipment is used by skilled or semi-skilled operators to produce tangible or intangible goods.

b) In the case of a hard rock mine, explosives are an example of transforming inputs.

c) The value added at a mine is the difference between the selling price of the mineral and the costs of inputs (per unit)



[1] b and c

[2] a and c

[3] a and b

[4] a, b and c

[5] None of the above options (1, 2, 3, or 4) is correct.

5. Read the following three statements:

a) Reliability is the probability that an item can be returned to a specified functional level within a specified time period.




b) Strategy at the enterprise level is a company’s large-scale future-orientated plans for interacting with the competitive environment in order to achieve company objectives.

c) Maintenance work can be outsourced – it does not have to be done in-house. Which of the above statements is/are correct?
[1] b and c

[2] a and c

[3] a and b

[4] a, b and c

[5] None of the above options (1, 2, 3, or 4) is correct

4. Read the following three statements:

a) The bathtub failure rate model provides for both wear-in as well as wear-out failures.

b) The Weibull distribution is often used to model increasing, constant or decreasing failure rates.

c) Information regarding the failure characteristics of an item are important when selecting a appropriate maintenance policy.



[1] b and c

[2] a and c

[3] a and b

[4] a, b and c

[5] None of the above options (1, 2, 3, or 4) is correct.

3. Read the following three statements:




a) Adjust, calibrate, inspect, etc. are some of the activities that take place during the maintenance transformation process.

b) Workers, spares, tools and information are all examples of resources used during the maintenance process.

c) Availability is the probability that an item will function without failure for a specified time under specified conditions.



[1] b and c

[2] a and c

[3] a and b

[4] b

[5] None of the above options (1, 2, 3, or 4) is correct.

2. Read the following three statements:

a) The purpose of modelling is to understand, predict, control and, ultimately, to improve.

b) Knowledge of the failure characteristics of an item is important when selecting appropriate maintenance action.

c) Continuous improvement is one of the features of total productive maintenance (TPM). Which of the above statements is/are correct?
[1] b and c

[2] a and c

[3] a and b

[4] b

[5] None of the above options (1, 2, 3, or 4) is correct.