What are the key characteristics of a Network Protocol? Why Protocol are needed?

Protocol is a set of rules that communicating entities must follow for orderly exchange of data.

Implementation of computer network is a complex task. Hence it is divided into number of layers. Suppose a layer n at source wants to communicate to a layer n at the destination, then there should be a standard mechanism so that both layers at same level should be able to talk to each other. The rules and conventions required for the communication are called as protocols. In general layered protocols must meet the following goals.

(a) Provide a logical decomposition of a complex network into smaller, more under-standable parts or layers.

(b) Provide symmetry in functions at each node in the network. Each layer performs the same functions as its counterpart in other nodes of the network.

(c) Provide a means to predict and control any changes made to network logic.

(d) Provide a standard language to clarify communication between network designers, manager and users.

What is Electronic Data Interchange (EDI)? Explain its salient features.

EDI is an Internet service provided for making commerce electronically known as e-commerce. It allows computer exchange of standard items like invoice, bills, orders, bank transfer etc. Features of EDI are:-

1. It reduces inventory costs

2. It displays information globally

3. Connects customer and seller at long distances

4. It automates the transaction process

5. It saves time, cost and energy

6. It transmits structured messages and provides strategic benefits.

What is meant by Information Systems? How are they different from a File System?

An Information System is a set of elements each of which is capable of carrying out certain information processing. All the elements performing the task of Information processing together for achieving a desired objective constitute an Information System. A personal computer is an example of Information System. An Information System in general consist of the following units

(1) Logical organizational units
(2) Computer hardware and software
(3) Information related personnels

File System is concerned with the logical organization of Information. File System deals with collection of unstructured and uninterpreted information. Each separately identified collection and information is called the File. A database management system is a file system that performs some structuring of information. We can functionally divide the file system into seven logical phases. They are:-

(a) Accessing methods
(b) Logical file system
(c) Basic file system
(d) File organisation strategy
(e) Allocation system strategy
(f) Device strategy
(g) I/O control system

A Programmer makes a request to read a file. He use a symbolic name. The logical file system accepts the symbolic name and finds the corresponding numeric file identifier. The basic file system takes the numeric file identifier and obtains a file descriptor. The file organisation strategy module uses the file descriptor to determine the physical address. The device strategy module produces the physical I/O commands to access the information (from where it is stored). I/O control system schedules the execution of the physical file commands.

Difference between Ink-Jet and Laser Printers with reference to their working.

Ink Jet Printers spray cyan, magenta, yellow and sometimes black ink onto a paper. Ink Jet are mounted on a head in a printer like mechanism. The print head moves across the page to draw one scan line, return while paper advances by one interscan line spacing and then draws next scan line. All colours are deposited simultaneously.

Laser Printers scan a laser beam across a positively charged rotating drum coated with selenium. The areas hit by the laser beam lose their charge and the positive charge remains only where the copy is to be black. A negatively charged powdered toner adheres to the positive areas of the drum and is then transferred to blank paper to form the copy. In Colour Printers this process is repeated three times once for each primary colour.

Distinguish between a text file and a binary file.

In a text file, bytes are treated as characters. Binary data is grouped into bytes and bytes are interpreted as characters based on some standard codes like ASCII or EBCDIC.

In a binary file the sequence of bits stored in file are not interpreted as characters. They may be executable code after compilation of program or graphics data or multimedia data. These bits are interpreted by the target user according to their specific purpose of creation.

What is DBMS? What are different types of DBMS? Compare these different types of DBMS?

A database management system is a collection of programs that enables users to create and maintain a database. It is a general purpose software system that facilitates the process of defining, constructing and manipulating databases for various applications.

There are three models available to organise the data sets in the form of databases. They are:

(a) Relational Model: In this model data elements are organised in the form of tuples (records) and set of tuples form tables.

(b) Hierarchial Data Base Model: In this model data organised in a hierarchial manner.

(c) Network Database Model: In this model related data items are linked by pointers to form a network. All related items can be accessed by tracking through the pointers (links).

Among the three database models relational database model is the most popular model. Network model has associated record at a time language that must be embedded in a host programming language. There is no standard language for the hierarchial model, although most hierarchial DBMS have record at time languages.

Calculate the degree of freedom for eutectic reaction for an iron-carbon alloy and an iron-chromium-nickel alloy, under 1 atmosphere.

Degree of freedom for eutectic reaction for an iron-carbon alloy under 1 atmosphere. According to phase rule or Gibbs rule. Eutectic reaction for an iron-carbon alloy have binary phase diagram.

F = C-P+2
F = Degree of freedom
C = Number of components
P = The number of phases

Here, in the case
C = 2, P = 2
so, F = 2-2+2=2
The degree of freedom for eutectic reaction for an iron-carbon alloy is 2

For iron-chromium-nickel alloy, the degree of freedom.
Here, in this case three component system give rise to ternary diagrams.
F = C-P+1
C = 3, P = 2
So, F = 3-3+1 = 1.

The degree of freedom for eutectic reaction for an iron-chromium nickel alloy is 1.

Brass has a peritectic reaction at a temperature of 903 degree C, with 36.8% Zn (beta phase) in the middle and 32.5% Zn at alpha phase end and 37.5% Zn at liquidus end. Find out the percentages of liquid phase and alpha phase present at the peritectic point.

Percentage of liquid phase = XZ/XY * 100
XZ = 37.5 - 36.8 = 0.7
XY = 37.5 - 32.5 = 5
= 0.7/5 * 100 = 14%
When the liquid reacts with the crystals precipitated out of liquid and forms new type of crystals.

Write down the Slip Plane and Slip Direction (one plane and one direction only) of Nickel (only Miller indices). How many slip systems are there in Nickel ?

A Slip Plane and a Slip Direction that lies on it together constitute a slip system. For example, the combination (111) and [110] forms a slip system, but not (111) and [110], as the [110] direction does not lie on the (111) plane.

Counting the slip systems for the most densely packed slip planes only, there are 12 slip systems in FCC and BCC crystals for Nickel.

Atomic radii of two metal atoms are 0.128 nm and 0.133 nm respectively. Find out whether they form an solid solution and if they form, state what type of solid solution it is.

%age change in radii
= 0.133-0.128/0.128
= 0.03906
= 3.91%
3.91% less than 15%
Hence they form solid solution, type of solid solution - solid solubility.

The final thickness of a hard copper sheet is 1.0 mm. It was produced by cold working with 25% deforestation. What was the starting thickness of the metal before the cold working ? To decrease the hardness what will you do ?

Final thickness of a hard copper sheet = 1.0 mm
25% deformed
Suppose, x = 0.25
So that 0.75x = 1
x = 1/0.75 = 1.33
To decrease the hardness, we will do further normalising.

Differentiate Between Culture and Civilization.

(a) Culture means development of tastes in art, literature and music whereas Civilization though quiet ancient yet is outcome of culture.

(b) Culture advances slowly and steadily whereas Civilization move continuously towards upward trend.

(c) Culture has instrinsic quality and cannot be adopted quickly whereas Civilization can be transferred from one generation to another quickly.

(d) Like mindedness is the basic requirement of culture whereas Civilization is passed with much efforts.

(e) Culture cannot be improved. How work of Milton and Tagore can be improved whereas work of Civilization can be improved by any body who has lesser thinking power.

What is the Role of Brain storming in design idea generation.


Brain storming is defined as a method to practice a conference technique by which a group attempts to find different concepts for a specific need by gathering or collecting all the ideas spontaneously contributed by its members.

In this stage brainstorming is important, however, we cannot use brainstorming without going through the process. The basic concept of brainstorming is to generate a large quantity of ideas. The more the ideas, higher the probability of the desired product.

The following are the members of the brainstorming session:

1. Designers
2. Engineers
3. Executives
4. Marketing experts
5. Psychology experts etc

Participants must be involved and achieve results in the session. The topics of brainstorming session is given to the members before the session starts and the duration of the session is upto an hour because the energy level needed for such session is high. A set of rules are developed for any brainstorming session.

1. No critism of ideas during the session. One way to prevent the critism is to disallow discussion during the session, present the ideas in brief and in short format. One of the participants in the group will need to collect all ideas or use a sticker for each idea.

2. Wild, silly and crazy ideas are welcome. Such ideas may help others to generate solid ideas or help for fun and humorous environment.

3. Generate as many ideas as possible. One way to do so is to appoint a facilitator who will keep rotating the turns without allowing break time. Keep the competition spirit alive. Some people produce more ideas when competing with others in a group.

4. Adding to or improving presented ideas are welcomed.

Techniques in use for brainstorming are:
1. Creative techniques
2. Osborn's Brain storming technique
3. Phillips 66 Buzz session technique
4. Crawford slip writing technique

Explain Robust Design.


A robust design is one in which the function and performance of the product or process are relatively insensitive to variations to any of the noise factors given below:

A noise factor is a source of variation that is impossible or difficult to control.

Type of noise factors--
1. Unit to Unit noise factor: These are random variations in the process and product caused by variability in raw materials, machinery and human participation. They are associated with a production process that is in statistical control.
2. Internal noise factor: These variations are internal to the product or process. They include (a) time dependant factor such as wear of mechanical component (b) operational errors, such as improper setting of the product or machine tool.
3. External noise factor: An external noise factor is a source of variation that is external to the product or process, such as temperature, pressure, voltage etc.

In product design, robustness means that the product can maintain consistent performance with minimal disturbance due to variations in uncontrollable factors in its operating environment.

In process design, robustness means that the process continues to produce good product with minimal effect from uncontrollable variations in its operating environment.

What do you mean by Social Mobility? What are the different types of Mobility?

Change from one status to another is called Social Mobility. Social Stratification is also the result of Social Mobility. Any change in the value-scale or any change in the characteristic results in a change in the status of different classes. Thus different occupations are held in different degrees of esteem in different societies. The members of priestly class enforced high rank at one time than that of a doctor and engineer in India. But today it is not like that. A doctor or engineer has more prestige and esteem. Thus it is experienced that people continue to move up and down in the status scale. This movement is called Social Mobility and should not be confused with migration which is called movement in geographical space. Social Mobility can take one of these forms. A change involving in an individual's life time turn one's status to another as plumber to that of carpenter is called horizontal mobility. Vertical Mobility can be either upward or downward.

Differentiate between standardization and specification giving appropriate examples. How are 'preferred numbers' useful in standardization? Explain with the help of a suitable example.

Standardization is the process of establishing standards or units of measure by which extent, quality, quantity, value performance, may be compared and measured.

The following standards are used for designing products:
(i) Standards for materials, their chemical compositions, their physical properties (e.g. mechanical) and heat treatment.
(ii) Standards for fits, tolerances and surface finish of components.
(iii) Different shapes and dimensions of commonly used machine elements e.g., nuts, bolts, rivets, gears etc.

Now the product specification includes such as dimensions of the components e.g. Volume, area, weight, speed, load, power etc. are expressed numerically e.g. 10 kw, 20 kN, 500 r.p.m or 10 kg etc.

Preferred numbers are used to specify such specification because a company may manufacture different models of same product.

The system is based on the use of geometric progressive to develop a set of numbers.

There are five basic series, denoted by R5, R10, R20, R40 and R80, which increased in steps of 58%, 26%, 12%, 6% and 3% respectively.

The series is obtained by taking the first number and multiplying it by a series factor to get the second number.

E.g. Consider a company manufacture of lifting machine who wants to introduce six different models of capacities ranging from 50kN to 100kN.

Considering R20 series, the capacity of different models of lifting machine will be 55 KN using R20 series--> 20/10 = 1.12

55 * 1.12 = 61.6 = 61 KN,
61 * 1.12 = 68.32 = 68kN,
68 * 1.12 = 76.16 = 70kN,
76 * 1.12 = 85.12 = 85kN,
85 * 1.12 = 95.2 = 95kN

Discuss the criteria for the assessment of appropriate technology.


Appropriate Technology: Be-fitting technology is called appropriate technology. Who do not want appropriate technology to feed the rapidly growing population. After all application of technology shall ensure optimum use of natural resources which may remain unutilized or underutilized in the absense of the same. No doubt in the past quarter of a century the developing countries like India have made progress in terms of increasing per capita income of their rapidly growing population. Of course progress has also been made in the fields of health, education and infrastructure (electricity, water, transportation and communication) but despite this growth record, poverty has not been lessened appreciably. Levels of unemployment and income inequality and increasing. According to the World Bank almost half of the total population of the developing world live in absolute poverty. Such people are denied basic components of average living, adequate clothing and housing and access to basic services such as clean water, energy, schools and health facilities which are taken for granted by most people in developed countries.

Appropriate technology means method of doing a given job or work in a benefiting manner and style as per the liking of users. We can say that an appropriate technology is one which is best suited to the environment in which it is most suitable. The idea of appropriate technology was first welcomed and received by third world countries. The third world countries are underdeveloped developing countries. India and host of many other countries are called third world countries. The concept of appropriate technology appeared first in the mind of great thinker Schumacher and we can find its reference in his famous work 'Small is Beautiful'.