(Please write your Roll No. immediately)

Roll No. ..................................

Time : 3 Hours

Maximum Marks : 75

Note : Attempt any 5 questions in all. Give freehand sketch where necessary.

Q1

( a )

Explain the following types of sand:

1. Facing sand 3. System sand

2. Backing sand 4. Parting sand

8

( b )

Why does the section of sprue reduce downwards?

3

( c )

What is the importance of permeability in molding sands?

2

( d )

Imagine a gating system without a riser. How does it affect the casting?

2

Q2

( a )

What is the difference between hot chamber and cold chamber die casting? Explain one process with suitable diagrams.

8

( b )

Explain centrifugal casting? How are the centrifugal casting methods classified?

3

( c )

Why is the mold in permanent mold casting preheated?

4

Q3

( a )

Define “forgeability”. On what factors does it depend?

3

( b )

Write short notes on swages, tongs and flatters used in a forging shop.

4

( c )

What is upset forging and how is it done?

3

( d )

How are a forging hammer and drop hammer alike and how do they differ?

5

Q4

( a )

Sketch and explain the working of an engineer's try square?

6

( b )

What are the advantages of a twist drill over flat drill?

4

( c )

What is the significance of accurate marking?

3

( d )

What is the difference between a mallet and a hammer?

2

Q5

( a )

Describe hems and seams used in sheet metal work.

6

( b )

Explain the utility of various allowances for making components by sheet metal work.

3

( c )

Differentiate between piercing, punching and blanking.

6

Q6

( a )

With the help of neat sketches explain the “spot welding method”.

5

( b )

Sketch the two polarities of DC supply and compare these for welding process.

4

( c )

What is the purpose of coating on an arc welding electrode?

3

( d )

Sketch the three types of flames used in oxy-acetylene. Gas welding give the uses of each.

3

Q7

( a )

Various edge preparations used for welding joints.

3 x 5

( b )

Difference between welding, soldering and brazing.

( c )

Types of files.

( d )

Binders used in molding sand.