preparetion for interviews in any company

                                             

Hiii I am Bhavit Sharma

How should we give interviews after going to any company ...

And how should we prepare for their question .  

100 Mechanical Engineering Interview Questions & Answer

1 October 2013 at 06:28

1. What is the difference between scavenging and supercharging ?

Ans:  Scavenging is process of flushing out burnt gases from engine cylinder by introducing fresh air in the cylinder before exhaust stroke ends. Supercharging is the process of supplying higher mass of air by compressing the atmospheric air. 

2. What are the names given to constant temperature, constant pressure, constant volume, constant internal energy, constant enthalpy, and constant entropy processes.

Ans:  Isothermal, isochroic, isobaric, free expression, throttling and adiabatic processes respectively. 

3. In a Rankine cycle if maximum steam pressure is increased keeping steam temperature and condenser pressure same, what will happen to dryness fraction of steam after expansion ?

Ans:  It will decrease. 

4. Why entropy change for a reversible adiabatic process is zero ?

Ans:  Because there is no heat transfer in this process. 

5. What are two essential conditions of perfect gas ?

Ans:  It satisfies equation of state and its specific heats are constant. 

6. Enthalpy and entropy are functions of one single parameter. Which is that ?

Ans:  Temperature. 

7. Why rate of condensation is higher on a polished surface compared to rusty surface ?

Ans:  Polished surface promotes drop wise condensation and does not wet the surface. 

8. How much resistance is offered to heat flow by drop wise condensation ?

Ans:  Nil 

How are these questions - please do add comments and if you like them please do share this post on facebook,  linkedin, twitter and google plus. 

To see the complete list of 100 questions, follow the link

http://mechanical-engineering.in/forum/blog/112/entry-387-mechanical-engineering-interview-questions-answer-best-of-luck-for-your-interview/

Mechanical Engineering interview  questions and answers Part 1   Part 2   Part 3   Part 4   Part 5   Part 6 1.What are the different types of fits? Explain? 2. What are the factors that can affect the Factor of safety selection? 3. What is heat treatment and why is it done? 4. What are the rules that must be kept in mind while designing castings? 5. What are the points that should be kept in mind during forging design? 6. Describe briefly the different cold drawing processes. 7. What are the different theories of failure under static load, explain briefly? What are the different types of fits? Explain? On the basis of Indian standards fits can mainly be categorized into three groups: > Clearance Fit: These types of fits are characterized by the occurrence of a clearance between the two mating parts. The difference between the minimum size of the hole and the maximum size of the shaft is called the minimum clearance, the difference between the maximum size of the hole and the minimum size of the shaft is known as maximum clearance. > Interference Fit: In these types of fits the size of the mating parts are predefined so that interference between them always occurs. The tolerance zone of the hole is completely below the tolerance zone of the shaft. > Transition Fit: As the name suggests these type of fit has its mating parts sized limited to allow either clearance or interference. The tolerance zone of the hole and the shaft overlaps in case of such fits. For a shaft designated as 40 H8/f7, calculate the tolerances. Given: Shaft designation = 40 H8/f7 The shaft designation 40 H8/f 7 means that the basic size is 40 mm and the tolerance grade for the hole is 8 ( i. e. I T 8) and for the shaft is 7 ( i. e. I T 7). Since 40 mm lies in the diameter steps of 30 to 50 mm, therefore the geometric mean diameter, D = Square root of (30 x 50) = 38.73 mm We know that standard tolerance unit, i = 0.45 x Cube root of (D) + 0.001 D i = 0.45 × 3.38 + 0.03873 = 1.559 73 or 1.56 microns i = 1.56 × 0.001 = 0.001 56 mm ...(1 micron = 0.001 mm) The standard tolerance for the hole of grade 8 (IT8) = 25 i = 25 × 0.001 56 = 0.039 mm The standard tolerance for the shaft of grade 7 (IT7) = 16 i = 16 × 0.001 56 = 0.025 mm What are the factors that can affect the Factor of safety selection? The factor of safety is used in designing a machine component. Prior to selecting the correct factor of safety certain points must be taken into consideration such as: > The properties of the material used for the machine and the changes in its intrinsic properties over the time period of service. > The accuracy and authenticity of test results to the actual machine parts. > The applied load reliability. > The limit of stresses (localized). > The loss of property and life in case of failures. > The limit of initial stresses at the time period of manufacture. > The extent to which the assumptions can be simplified. The factor of safety also depends on numerous other considerations such as the material, the method of manufacturing , the various types of stress, the part shapes etc. What is heat treatment and why is it done? Heat treatment can be defined as a combination of processes or operations in which the heating and cooling of a metal or alloy is done in order to obtain desirable characteristics without changing the compositions. Some of the motives or purpose of heat treatment are as follows: > In order to improve the hardness of metals. > For the softening of the metal. > In order to improve the machinability of the metal. > To change the grain size. > To provide better resistance to heat, corrosion, wear etc. Heat treatment is generally performed in the following ways: > Normalizing > Annealing > Spheroidising > Hardening > Tempering > Surface or case hardening What are the rules that must be kept in mind while designing castings? Some of the points that must be kept in mind during the process of cast designing are as follows: > To avoid the concentration of stresses sharp corners and frequent use of fillets should be avoided. > Section thicknesses should be uniform as much as possible. For variations it must be done gradually. > Abrupt changes in the thickness should be avoided at all costs. > Simplicity is the key, the casting should be designed as simple as possible. > It is difficult to create true large spaces and henceforth large flat surfaces must be avoided. > Webs and ribs used for stiffening in castings should as minimal as possible. > Curved shapes can be used in order to improve the stress handling of the cast. What are the points that should be kept in mind during forging design? Some of the points that should be followed while forging design are: > A radial flow of grains or fibers must be achieved in the forged components. > The forged items such as drop and press forgings should have a parting line that should divide the forging into two equal halves. > The ribs in a forging should not be high or thin. > In order to avoid increased die wear the pockets and recesses in forgings should be minimum. > In forgings the parting line of it should lie as far as possible in a single plane. > For ease of forging and easy removal of forgings the surfaces of the metal should contain sufficient drafts. Describe briefly the different cold drawing processes. Some of the important cold drawing processes are as follows: > Bar and Rod Drawing: In the case of bar drawing the hot drawn bars are at first pickled, washed and coated to prevent oxidation. Once this is done a draw bench is used for the process of cold drawing. In order to make an end possible to enter a drawing die the diameter of the rod is reduced by the swaging operation. This end is fastened by chains to the draw bench and the end is gripped by the jaws of the carriage. In this method a high surface finish and accuracy dimensionally is obtained. The products of this process can be used directly without any further machining. > Wire Drawing: Similar to the above process the bars are first pickled, washed and coated to prevent any oxidation. After this the rods are passed through several dies of decreasing diameter to provide a desired reduction in the size ( diameter ). The dies used for the reduction process is generally made up of carbide materials. >Tube Drawing: This type of drawing is very similar to the bar drawing process and in majority of cases it is accomplished by the use of a draw bench. What are the different theories of failure under static load, explain briefly? The main theories of failure of a member subjected to bi-axial stress are as follows: > Maximum principal stress theory ( Rankine’s theory): This theory states that failure occurs at a point in member where the maximum principal or normal stress in a bi-axial system reaches the maximum strength in a simple tension test. > Maximum shear stress theory ( Guest’s or Tresca’s theory): This theory states that failure occurs when the biaxial stress reaches a value equal to the shear stress at yield point in a simple tension test. > Maximum principal strain theory ( Saint Venant theory): This theory states that failure occurs when bi-axial stress reaches the limiting value of strain. > Maximum strain energy theory ( Haigh’s theory): This theory states that failure occurs when strain energy per unit volume of the stress system reaches the limiting strain energy point. > Maximum distortion energy theory ( Hencky and Von Mises theory): This theory states that failure occurs when strain energy per unit volume reaches the limiting distortion energy. Part 1   Part 2   Part 3   Part 4   Part 5   Part 6

   


                                                                                                                                                                        

     
     
     
     
     
    


      




     

 Today I want to tell you about Train EngineHome > Arts and Crafts Projects for Kids > Vehicles / Transportation Crafts > Train & Locomotive Crafts

TRAIN CRAFTS FOR KIDS: Ideas to make choo choo trains & locomotives with easy arts and crafts decorations, instructions, patterns, and activities for children, preschoolers, and teens

A train is a form of rail transport consisting of a series of vehicles propelled along a rail track to transport cargo or passengers. Most children love trains. They are fascinated by big, load and powerful things.

If you are looking for project ideas on how to entertain your kids on a rainy afternoon, then making trains at home is the best and fun way to go. Your children can make a train from candy, its fun and kids can eat candy while they make it. They can also make a train from paper or an egg carton. You can also make a train from juice boxes too!

Below you will find Train & Locomotive Crafts Arts and Crafts Projects Ideas for your Kids. Find out how to make your own arts and crafts Choo Choo Trains & Locomotives projects with the following decorations, instructions, patterns, and activities for children

Make Traveling Circus Zoo Animal Train Cage

An entire traveling circus, carnival or zoo can be made if you have enough of these cages for all the animals. Remove the sliding drawer from a matchbox and throw away the matches as you will not need them. You may also discard the matchbox cover. Paint the matchbox drawer inside and out, and allow it to dry thoroughly. Glue a row of toothpicks inside the box on all 4 sides to make the bars of the cage. Cut out 4 tiny circles of thin cardboard for the wheels and paint them a bright color. Allow them to dry. Attach the wheels to the cage with straight pins. Push the pins through the center of the wheels and bend the pins inside the box so that the wheels won't slip off. Place a tiny toy animal in the cage. Cut a piece of white paper a little larger than the cage for an awning. Make stripes on the awning with paints or crayons. Place the awning over the toothpick bars, forcing the tips of the toothpicks through the paper. Add 2 toothpick handles and the cage is ready to roll.

Making Shoe Box Trains Craft

Remove the covers from 3 or 4 shoe boxes. Punch a hole near the bottom of each of the box ends. Obtain a length of cord or string that is long enough to pass through the insides of the boxes and to provide a length for pulling the train. Then tie a clothespin on one end of the cord. Beginning on the outside of one box, run the cord through the hole so that it comes through into the inside of the box. The clothespin will prevent the cord from slipping out of the end of the box. Pull the cord along the bottom of the box and out the other end of the box, as seen in figure 1. Knot a second clothespin on the outside of this end of the box, as seen in figure 2. Then run the cord through the other boxes in the same way, as seen in figure 3. Be sure to knot a clothespin at the other end of the rope. This will make a handle. The shoe box train is now ready to be loaded with toys and pulled across the room by a toddler.

Making Ride-On Pretend Toy Trains

Find a bunch of big cardboard boxes. You can create your own cardboard trains or look at the picture above to help guide you towards creating a ride-on train. Use paper plates for wheels...glue them on the boxes. The first box isn't a sit-in box, it is just the front of the train. Make it face down and bring the side flap up and cut a window out of it. Attach a steering wheel paper plate to the box with glue or a brass paper fastener. The 2nd box car should have a rectangle portion cut out of it...this is the car that you can sit in. The remaining cars in the back could be whatever you want...but should be open at the top so that people or toys can sit in there. You can glue the boxes together or attach them with poked holes then strung with string and knotted together. It is all up to you and your creativity...have a train-ful of fun!

Even More Choo Choo Trains Crafts You Can Make

Use box-tops for the bases of all the cars for this train, and milk bottle tops or button moulds for their wheels. Attach the wheels to the bases with two-pronged paper fasteners. Fasten loosely enough to allow the wheels to turn easily. To make the tops of the cars use smaller boxes than those used to make the bases. Use an oatmeal box for the top part of the engine. Glue in place. Cut little slits in the box for the stacks and bell. Make the bell and stacks from black construction paper. Decorate each car according to its use.

Paper Train Whistles

Obtain a piece of paper. Fold it into 4 parts, as pictured in Figure 1. Cut a hole in center fold, as seen in Figure 2. Then hold the front fold against your lips and blow into it. You will be delighted with the first class whistle you have made for your train.

More Train Ideas

 Advent Choo Choo Train Craft for Kids - Countdown to Christmas in a different way this year with an Advert Choo Choo Train.

 All Aboard Choo Choo Train Arts & Crafts Project - Encourage your children to use their imagination to create their own choo choo train using crayola products and materials around the house.

 All Aboard for these Preschool Train Crafts! - These are simple and fun crafts for the young preschoolers to enjoy.

 Amigurumi - Sushi Train Toy to Make - This train craft is for the older children and adults who can crochet.

 Animal Cracker Circus Trains Craft for Preschoolers & Toddlers - Make a cool circus train for your animal crackers.

 Animal Train Arts Activity for Youngsters - Your children will have tons of fun making and coloring their own animal train.

 Build Your Own Train: Steam Engine - Print and follow the instructions to build a steam engine plane.

 Choo-Choo Train Growth Chart - Learn how to make a colorful choo-choo train growth chart by following these instructions.

 Christmas Train Paper Craft - Print the template and follow the instructions to put together a paper Christmas train.

 Chugga-chugga Choo choo! Train Craft - Your kids can create a train using constructions paper, scissors, tape, glue cotton balls and other materials.

 Cork Trains Craft for Children - Make a train out of wine corks!

 GG1-type Electric Locomotive - Print the GG1-type Electric Locomotive train template and follow the instructions.

 Here Comes a Train! - Have your kids use their imagination with the help of Crayola products to design their own train.

How to Make a Cardboard Box Train - Find out how you can make a train out 5 show boxes, 3 large paper clips, toilet paper tube and other basic materials.

 How to Make a Paper Train- Learn how you can make a paper train by following these instructions.

 How to Make a Train Pinata - Make a very cool train piñata for your train themed birthday party.

 How to Make a Train Using Paper - All children love to make a train out of paper! Follow these instructions to make your own.

How to Make a Train With Egg Cartons - Learn how to make a train using an egg carton, paint, paper and other materials by following these instructions.

 How to Make Kids Candy Train Party Favor Craft - Make a cool edible train with your children. This is also a great birthday party craft.

 Japan Railway E1 Max Bullet Train PaperCraft Model - Print the template of the Japan Railway E1 Max Bullet Train and follow the instructions to put it together.

Juice Box Train - Your children can reuse their juice boxes to make a cute recycled train.

 Love Train - This Valentine's Day make someone special a sweet love train.

Ni Hao, Kai-lan Tissue Box Train - Make a cool tissue box train with your friends Ni Hao and Kai-lan.

 Recycled Train Craft - Make a train from recycle items such as a tin can and some Snapple tea lids for the wheels.

 Steam Train - Make yourself the driver of a steam train..

 Super express train - Print out the pattern of this Super Express Train and have your kids put it together.

 Thomas the Tank Engine Paper Craft- - Follow this simple craft and make your own Thomas the tank engine train.

 Tin Can Train - Use different size and shape tin cans and other recycled materials to make a train at home with your kids.

 Toddler Train Craft - Help your toddler make their own train with simple materials such as construction paper, cereal boxes and crayons.

 Train Across Canada - Enjoy the scenery of Canada with this cool train craft.

 Train Beaded Safety Pin Design - Make a beaded safety pin train design by following the giving pattern and instructions.

 Train Costume - Find out how you can make a Halloween train costume with your children.

 Train Crafts for Older Kids - This website will show you different train crafts for older children they can do at home.

 Train Models - Learn how to make model trains using the available free pattern.

 Train Ornaments - Make a train ornament for your Christmas tree that you and your kids will cherish.

 Train Pattern for Beaded Saftey Pin - Use the free train pattern given to make a beaded safety pin jewelry.

 Train Passenger Car Paper Craft - Print the train passenger car on paper and follow the instructions carefully.

 Trains - Encourage your children to use their imagination to design their own paper train.

 Train Wind Chimes - Turn a wooden train kit into the most beautiful train wind chimes.