Engineering Teach: 2013

Saturday 7 December 2013

"Century Innovations"

20th Century Innovation Topics:

1. Electrification
2. Automobile
3. Airplane
4. Water supply and distribution
5. Electronics
6. Radio and television
7. Agricultural mechanization
8. Computers
9. Telephone
10. Air conditioning/refrigeration
11. Interstate highways
12. Space flight
13. Internet
14. Imaging
15. Household appliances
16. Health technologies
17. Petrochemical technology
18. Laser and fiber optics
19. Nuclear technologies
20. High-performance materials

21st Century Innovation Topics:

1. Energy conservation
2. Resource protection
3. Food and water production and distribution
4. Waste management
5. Education and learning
6. Medicine and prolonging life
7. Security and counter-terrorism
8. New technology
9. Genetics and cloning
10. Global communication
11. Traffic and population logistics
12. Knowledge sharing
13. Integrated electronic environment
14. Globalization
15. AI, interfaces and robotics
16. Weather prediction and control
17. Sustainable development
18. Entertainment
19. Space exploration
20. "Virtualization" and VR
21. Preservation of history
22. Preservation of species

Sunday 1 September 2013

"All Department Engineering Notes"

Some of the blog/website below gives "All Department Engineering Notes"

1. Civil Engineering:
http://civilengineerblogger.blogspot.in/p/free-civil-engineering-books-and.html

2. For all department notes and videos:
http://nptel.iitm.ac.in/courses.php

3. Engineering notes/books for all departments especially for CSE and IT department:
http://engineeringppt.net

4. All engineering department notes/books for download:
http://www.enggnotes.in/home.php?rt=rt

5. Engineering (All departments) Notes/Downloads:
http://technicalsymposium.com/alldepartment_lecturenotes.html#.UiJVptLinQQ

6. For Engineering (All branches) Written Notes:
http://www.ululu.in/notes/

If you like this share with your friends also...

MBA Notes/Books Websites:

Here some of the website address given below toget the MBA notes:

1. http://www.ignou4ublog.com/2010/11/ignou-mba-books-download-ignou-mba.html

2. http://www.mbanotes.gurukpo.com

3. http://mbanotes.in/subject-list.php?type=sub&page_name=n
a) http://mbanotes.in/subject-list.php?type=1&page_name=n
b) http://mbanotes.in/subject-list.php?type=2&page_name=n
c) http://mbanotes.in/subject-list.php?type=3&page_name=n
d) http://mbanotes.in/subject-list.php?type=4&page_name=n

Hope this will help...

MBA Notes: Total Quality Management

1. Total Quality Management:

Click the below link to download the Notes:
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MBA Notes: Strategic Management

1. Strategic Management:

Click the below link to download the Notes:
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Wednesday 7 August 2013

"Important Websites For Engineering Students and Engineers"

1.For Free download engineering ppt pdf slides lecture notes seminars
http://engineeringppt.blogspot.in/

2. For BE/ME/B.TECH/M.TECH ENGINEERING & LECTURER NOTES & QUESTION PAPERS, GENERAL TOPICS,INTERVIEW QUESTIONS,APTITUDE PAPERS,MODEL PAPERS,PLACEMENT PAPERS, EXAM RESULTS,ANNA UNIVERSITY REVALUATION RESULTS 2012 & MANY MORE....
http://shareengineer.blogspot.in

3. For Engineering projects ideas for final year students & paper presentations collection blog.

http://hello-engineers.blogspot.in/

4. For DOWNLOAD FREE LECTURE NOTES SLIDES PPT PDF EBOOKS

This Blog contains a huge collection of various lectures notes, slides, ebooks in ppt, pdf and html format in all subjects. My aim is to help students and faculty to download study materials at one place.

http://lecturesppt.blogspot.in/

Monday 24 June 2013

Electrical Engineering: Protection and Switchgears

1. What are the functions of protective relays
To detect the fault and initiate the operation of the circuit breaker to isolate the defective element from the rest of the system, thereby protecting the system from damages consequent to the fault.

2. Give the consequences of short circuit.
Whenever a short-circuit occurs, the current flowing through the coil increases to an enormous value. If protective relays are present , a heavy current also flows through the relay coil, causing it to operate by closing its contacts.The trip circuit is then closed , the circuit breaker opens and the fault is isolated from the rest of the system. Also, a low voltage may be created which may damage systems connected to the supply.

3. Define protected zone.
Are those which are directly protected by a protective system such as relays, fuses or switchgears.If a fault occurring in a zone can be immediately detected and or isolated by a protection scheme dedicated to that particular zone.

4. What are unit system and non unit system?
A unit protective system is one in which only faults occurring within its protected zone are isolated.Faults occurring elsewhere in the system have no influence on the operation of a unit system.A non unit system is a protective system which is activated even when the faults are external to its protected zone.

5. What is primary protection?
Is the protection in which the fault occurring in a line will be cleared by its own relay and circuit breaker.It serves as the first line of defence.

6. What is back up protection?
Is the second line of defence , which operates if the primary protection fails to activate within a definite time delay.

7. Name the different kinds of overcurrent relays.
Induction type non-directional overcurrent relay,Induction type directional overcurrent relay & current differential relay.

8. Define energizing quantity.
It refers to the current or voltage which is used to activate the relay into operation.

9. Define operating time of a relay.
It is defined as the time period extending from the occurrence of the fault through the relay detecting the fault to the operation of the relay.

10. Define resetting time of a relay.
It is defined as the time taken by the relay from the instant of isolating the fault to the moment when the fault is removed and the relay can be reset.

11. What are over and under current relays?
Overcurrent relays are those that operate when the current in a line exceeds a predetermined value. (eg: Induction type non-directional/directional overcurrent relay, differential overcurrent relay)whereas undercurrent relays are those which operate whenever the current in a circuit/line drops below a predetermined value.(eg: differential over-voltage relay)

12. Mention any two applications of differential relay.
Protection of generator & generator transformer unit; protection of large motors and busbars.

13. What is biased differential bus zone reduction?
The biased beam relay is designed to respond to the differential current in terms of its fractional relation to the current flowing through the protected zone. It is essentially an over-current balanced beam relay type with an additional restraining coil. The restraining coil produces a bias force in the opposite direction to the operating force.

14. What is the need of relay coordination?
The operation of a relay should be fast and selective, ie, it should isolate the fault in the shortest possible time causing minimum disturbance to the system. Also, if a relay fails to operate, there should be sufficiently quick backup protection so that the rest of the system is protected. By coordinating relays, faults can always be isolated quickly without serious disturbance to the rest of the system.

15. What is an under frequency relay?
An under frequency relay is one which operates when the frequency of the system (usually an alternator or transformer) falls below a certain value.

16. What are the features of directional relay?
High speed operation; high sensitivity; ability to operate at low voltages; adequate short-time thermal ratio; burden must not be excessive.

17. What are the causes of over speed and how alternators are protected from it?
Sudden loss of all or major part of the load causes over-speeding in alternators. Modern alternators are provided with mechanical centrifugal devices mounted on their driving shafts to trip the main valve of the prime mover when a dangerous over-speed occurs.

18. Define an under current relay?
Relays which operates whenever the current in a circuit drops below a predetermined value.

19. Differentiate between a fuse and a circuit breaker.
Fuse is a low current interrupting device. It is a copper or an aluminium wire.Circuit breaker is a high current interrupting device and it act as a switch under normal operating conditions. 30. How direct tests are conducted in circuit breakers? Using a short circuit generator as the source. Using the power utility system or network as the source.

20. What is dielectric test of a circuit breaker?
It consists of over voltage withstand test of power frequency lightning and impulse voltages.Tests are done for both internal and external insulation with switch in both open and closed conditions.

21. What is the backup protection available for an alternator?
Overcurrent and earth fault protection is the backup protections.

22. What is REF relay? It is restricted earth fault relay.
When the fault occurs very near to the neutral point of the transformer, the voltage available to drive the earth circuit is very small,which may not be sufficient to activate the relay, unless the relay is set for a very low current. Hence the zone of protection in the winding of the transformer is restricted to cover only around 85%. Hence the relay is called REF relay.

23. Why busbar protection is needed?
(a) Fault level at busbar is high (b) The stability of the system is affected by the faults in the bus zone. (c) A fault in the bus bar causes interruption of supply to a large portion of the system network.
24. What are the errors in CT?
(a) Ratio error Percentage ratio error = [(Nominal ratio – Actual ratio)/Actual ratio] x 100 The value of transformation ratio is not equal to the turns ratio. (b) Phase angle error: Phase angle =180/ [(ImCos -I1Sin )/nIs]

25. What is circuit breaker?
It is a piece of equipment used to break a circuit automatically under fault conditions. It breaks a circuit either manually or by remote control under normal conditions and under fault conditions.

26. Write the classification of circuit breakers based on the medium used for arc extinction?
Air break circuit breaker Oil circuit breaker Minimum oil circuit breaker Air blast circuit breaker SF6 circuit breaker Vacuum circuit breaker

27. Define a over current relay.
Relay which operates when the current ia a line exceeds a predetermined value.

28. What are the uses of Buchholz’s relay?
Buchholz relay is used to give an alarm in case of incipient( slow-developing) faults in the transformer and to connect the transformer from the supply in the event of severe internal faults. It is usually used in oil immersion transformers with a rating over 750 KVA.

Civil Engineering interview questions and answers

Civil engineering is one of the oldest branches of engineering that deals with the design, construction and maintenance of buildings, roads, bridges, artificial waterways, dams etc. Civil engineers have shown their expertise from time immemorial. From the Roman Pantheon to Hong Kong international airport, civil engineers have excelled in every step. Interview questions for civil engineers include strength of materials, material science, energy engineering, environmental engineering and earthquake engineering.

Define Modulus of Elasticity?
Modulus of Elasticity, also know as elastic modulus is the elastic deformation tendency of a material. In the stress strain curve the slope is the elastic modulus.
What is the chemical composition of cement?
Cement primarily consists of CaO. The chemical composition of Portland cement is tricalcium silicate, dicalcium silicate, tricalcium aluminate and tetracalcium aluminoferrite.
What is tensile strength?
It is the maximum longitudinal stress that an object can withstand without necking. It denotes the maximum point in a stress strain curve.
Which is the world’s largest hydroelectric project?
The Three Gorges dam on Yangtze River in China is the world’s largest hydroelectric project in terms of total capacity. The total capacity of the Three Gorges dam upon full completion would be 22500 MW with 32 turbines. Its length is 2335m and height is 101m. The second largest is the Itaipu dam on the Parana River in the border of Brazil and Paraguay. Its length is 7700m and height is 196m with a capacity of 14GW in 20 turbines.
Explain soil analysis.
Soil testing is a qualitative analysis to determine the nutritional and elemental composition of soil. Soil is mostly tested for elements such as nitrogen, phosphorus and potassium. It is also tested for acidity, moisture, organic contents and contaminants.
What are the points in the stress strain curve for mild steel?
The points in the stress strain curve for mild steel are Proportional limit, elastic limit or yield point, ultimate stress and stress at failure.
What are building codes?
Building codes are a set of specifications regarding minimum safety conditions that any building should take in account during construction. Building codes deal with the height, spacing, installations of a building. These codes lay huge emphasis on safety and ease to evacuate the building in case of an emergency.
What is fire resistance rating?
It is a measure of time up to which a system could resist the fire resistance test. It is generally depicted by a time-temperature graph.
What are tectonic plates?
Tectonic plates are the pieces of the Earth’s lithosphere. The lithosphere lies over the asthenophere, which has a higher density and makes the tectonic plates on the lithosphere to move. The movement of the tectonic plates is said to be the cause of earthquakes. Ocean trenches, volcanoes and mountains exist at the meeting points of two tectonic plates.
What is the Richter scale?
The Richter scale, a base 10 logarithmic scale, is a measure to quantify the seismic energy from an earthquake.

Mechanical Engineering Interview Questions with answers

1. What is the difference between Technology and Engineering?Ans. Engineering is application of science. Technology shows various methods of Engineering. A bridge can be made by using beams to bear the load,by an arc or by hanging in a cable; all shows different technology but comes under civil engineering and science applied is laws of force/load distribution.

2. How to Measure Temperature in Wet Bulb Thermometer?Ans. Wet bulb temperature is measured in a wet bulb thermometer by covering the bulb with a wick and wetting it with water. It corresponds to the dew point temperature and relative humidity.

3. What are the Advantages and Disadvantages of using LPG in Car?Ans. Advantages
1. Complete combustion 2. Fuel saving 3. Homogenous combustion
Disadvantages
1. As complete combustion is occurring ,more heat liberated,not advised for long journey, engine will be over heated 2. Installation is difficult 3. Reduce engine life efficiency

4. What is the difference between Speed and Economic Speed? Ans. The rated speed tells us about the maximum speed which can be achieved by a vehicle or some other machine but the economical speed means the speed limit at which the machine works efficiently with least consumption of fuel.eg-in normal bikes(not racing),the max.speed limit shown on speedometer is upto 120 kmph but companies always advice their customers to drive such bikes at around 60 kmph to have maximum mileage.

5. What is Powder Technology?Ans. Powder technology is one of the ways of making bearing material. In this method metals like bronze, Al, Fe are mixed and compressed to make an alloy.

6. State all the laws of Thermodynamics?Ans. There are three laws of the thermodynamics. First Law: Energy can be neither created nor destroyed. It can only change forms. In any process in an isolated system, the total energy remains the same. Second Law: When two isolated systems in separate but nearby regions of space, each in thermodynamic equilibrium in itself, but not in equilibrium with each other at first, are at some time allowed to interact, breaking the isolation that separates the two systems, and they exchange matter or energy, they will eventually reach a mutual thermodynamic equilibrium. The sum of the entropies of the initial, isolated systems is less than or equal to the entropy of the final exchanging systems. In the process of reaching a new thermodynamic equilibrium, entropy has increased, or at least has not decreased. Third Law: As temperature approaches absolute zero, the entropy of a system approaches a minimum.

Wednesday 1 May 2013

MBA Notes_Operations Research

Operations Research: Full Topics Link in PDF as below

Electronics and Communication Engineering: Question and Answers

1.What is CDMA?

CDMA stands for Code Division Multiple Access which uses digital format. In CDMA systems several transmissions via the radio interface take place simultaneously on the same frequency bandwidth. User data is combined at the transmitter’s side with a code, then transmitted. On air, all transmission get mixed. At the receiver's side the same code is used as in the transmitter’s side. The code helps the receiver to filter the user information of the transmitter from incoming mixture of all transmissions on the same frequency band and same time.

2.Explain the concept of frequency re-use.

The whole of the geographical area is divided into hexagonal shape geometrical area called cell and each cell having its own transceiver. Each BTS (cell site) allocated different band of frequency or different channel. Each BTS antenna is designed in such a way that i cover cell area in which it is placed with frequency allotted without interfering other cell signals. The design process of selecting and allocating channel groups for all of the cellular base station within system is called frequency reuse.

3.Explain Bluetooth.

Bluetooth is designed to be a personal area network, where participating entities are mobile and require sporadic communication with others. It is omni directional i.e. it does not have line of sight limitation like infra red does. Ericsson started the work on Bluetooth and named it after the Danish king Harold Biuetooth. Bluetooth operates in the 2.4 GHz area of spectrum and provides a range of 10 metres. It offers transfer speeds of around 720 Kbps.

4.What are applications of DSP?

Some selected applications or digital signal processing that are often encountered in daily life are listed as follows:
1. Telecommunication: Echo cancellation in telephone networks.
2. Military Radar signal processing
3. Consumer electronics Digital Audio/TV
4. Instrumentation and control
5. Image processing image representation, image compression
6. Speech processing speech analysis methods are used in automatic speech recognition
7. Medicine Medical diagnostic instrumentation such as computerised tomography (CT)
8. Seismology DSP techniques are employed in geophysical exploration for oil and gas.
9. Signal Filtering Removal of unwanted background noise.

5.Explain radio environment in building.

Building penetration : Building penetration depends on the material used for construction and architecture used. This varies building to building and is based on building construction.
Building Height Effect : The signal strength is always higher at top floor and generally floor gain height is about 2.7dB/floor which is not dependent on building construction.
Building Floor Reception : The signal isolation between floors in a multi floor building is on the average about 20dB. Within a floor of 150 * 150 feet, the propagation loss due to interior walls, depending on the wall materials is about 20 dB between the strong and the weak areas.

6.List some advantages of GSM.

Here are some advantages of GSM :
1. GSM is mature, this maturity means a more stable network with robust features.
2. Less signal deterioration inside buildings.
3. Ability to use repeaters.
4. Talk time is generally higher in GSM phones due to pulse nature of transmission.
5. The availability of Subscriber Identity Modules allows users to switch networks and handset at will.
6. GSM covers virtually all parts of world so international roaming is not a problem.

7.What are the various types of numbers for network identity?

Various types of number for network identity are as follows :
1. MSISDN ( Mobile station ISDN) Number : It is international mobile subscriber number which is normally called mobile number. It is unique worldwide.
2. MSRN ( Mobile Subscriber Routing Number) : MSRN is used during mobile terminate trunk call to provide location of mobile subscriber.
3. HON ( Hand Over Number ) : HON is used for providing information required to transfer call from one B?SC to another BSC or to another MSC.
4. ISMI ( International Mobile Subscriber Identity Number) : Purpose of ISMI is for location update and authentication.
5. TMSI ( Temporary Mobile Subscriber Identity ) : TMSI is used instead of IMSI to improve security efficiency of network.
6. IMEI : International Mobile Equipment Identity.

8.What are GPRS services?

GPRS services are defined to fall in one of the two categories :
- PTP ( Point to point)
- PTM ( Point to Multipoint)
Some of the GPRS services are not likely to be provided by network operators during early deployment of GPRS due in part to the phased development of standard. Market demand is another factor affecting the decision of operators regarding which services to offer first.

9.What are the advantages of spread spectrum?

SPread spectrum has the following advantages :
1. No crosstalk interference.
2. Better voice quality/data integrity and less static noise.
3. Lowered susceptibility to multipath fading.
4. Inherent security.
5. Co-existence.
6. Longer operating distances.
7. Hard to detect.
8. Hard to intercept or demodulate.
9. Harder to jam than narrow bands.
10. Use of ranging and radar.

10.Explain the steps involved in demodulating a signal.

Once the signal is coded, modulated and then sent, the receiver must demodulate the signal. This is usually done in two steps :
1. Spectrum spreading (e.g., direct sequence or frequency hopping) modulation is removed.
2. The remaining information bearing signal is demodulated by multiplying with a local reference identical in structure and synchronised with received signal.

Sunday 14 April 2013

Civil Engineering_Question and Answers_Part:2

Open this link to get "

200 Questions and Answers on

Practical Civil Engineering Works"

http://engineeringteach.blogspot.in/

Civil Engineering_Question and Answers_Part:1

1 . What are the causes of building collapse? The Passage of time is one reason. Buildings also collapse due to weak foundations. Earthquakes, hurricanes and other natural disasters can also damage the structure of the buildings and cause it to collapse. Bombings or demolition of buildings is also other reasons.

2. What are the applications of modulus of elasticity? As the term implies, "Modulus of Elasticity” relates to the elasticity or "flexibility" of a material. The value of modulus of elasticity is very much significant relating to deflection of certain materials used in the construction industry. Take for example the general E value of mild carbon steel is about 200 GPA compared to about 70 GPA for aluminum. This simply translate that aluminum is 3 times flexible than steel.

3. How are freeway bridges built? After calculating the anticipated traffic for the bridge, cement/reinforced- with- rebar stanchions are spaced over the freeway to accommodate the bridge. An 'off-ramp' from the freeway to the bridge is constructed, as is an 'on-ramp' to the subsequent road. Cement/rebar slabs are built and lifted with cranes to form the platform, and voila! Drive carefully. Although the bridge deck/roadway is almost always a concrete slab, the structure that holds up the bridge deck can be reinforced concrete, structural steel, or a combination of steel and concrete.

4. What is rigging? In sailing, the ropes used to move the sails around so the boat will move in the right direction when the wind blows.

5. What is the difference between engineering stress and true stress? In biology, Stress is something that disrupts homeostasis of an organism. In engineering, Stress is an external force that pushes, pulls, twists, or otherwise puts force on something. Engineering stress assumes that the area a force is acting upon remains constant, true stress takes into account the reduction in area caused by the force.

6. What is the meaning of soil reinforcement? Soil reinforcement is the act of improving soil strength to enable it support or carry more load. Two common examples are: a) Mixing a soil amendment such as lime into weak clayey soil and re-comPActing to improve soil-bearing caPAcity (often done under the road base in highway construction), b) Installing plastic or composite webbing layers (called geo-grid material) alternating with comPActed soil to produce a stronger sloped soil structure (often done on steep roadway embankments to improve strength and stability)

EEE_Question-Answers

1. How are the power correction capacitors available?

They are sold at a specific voltage rating by kVAR. They are sold in a trio of three capacitors. They are connected to induction motors and switched.

2. A star delta starter is used with induction motor. What is the reason behind it and mention its advantages?

The main advantage of using a star delta starter with induction motor is that the less amount of current can be made use of during the starting of the motor. Hence the current spent in total is also reduced.

3. What is the use of a circuit breaker? Is it same as that of a fuse?

It is different from that of a fuse. It is used to reset the protective device. When heavy loads of input flows in, the fuse cuts of the internal connection and this breaker resets the protective device alerting it for safeguarding the entire unit.

4. What can be the voltage gain of the voltage follower?

A voltage follower is a device whose output will merely just follow the input and hence won’t have any gain.

5. In power systems, what is the prime method that is followed to improve power quality?

A capacitor bank can be connected in series with the load which will result in the improvement of the overall power factor and power supply.

6. Why are the transformers’ current measures in kVA?

kVa is basically a unit that is used to measure apparent power which is a combination of active and reactive power. The transformer current generally includes the higher frequencies like the harmonics. Hence kVA is the easy way of measuring this type of current.

7. What is known as regenerative breaking?

It is a general phenomenon that a motor continues running even after the power is cut off. This is due to the residual inertia. A load resistor is placed in the unit to prevent the motor from running after the power cut. The back e.m.f voltage is applied back across the resistor and due to this load the motor stops running. This entire mechanism is called as regenerative breaking.

8. Where is the output of an RC integrator taken across?

RC is a combination of resistor and capacitor. When load is applied across this unit, the output is obtained from the capacitor.

9. What is the two terminal voltage variable resistor popularly known as?

It is known as Rheostat.

10. Why is DC flow of current blocked in a capacitor?

A capacitor’s reactance is inversely proportional to the frequency. For d.c. current there is no frequency and hence the reactance of the capacitor becomes infinite. This is the reason why a capacitor blocks DC.

11. A humming sound occurs in the HT transmission. Why is that?

Ionization occurs due to the air break down in to the charged particles around the transmission conductors. This is the reason behind the humming sound and it is technically known as corona effect. In lay men terms it is a form of power loss.