Question

Which ONE or MORE among the following options CORRECTLY match(es) the type of defects with the corresponding metal working processes in which they are likely to occur?

Defect Code	Defect	Process Code	Process
P	Centerburst	1	Deep drawing
Q	Earing	2	Rolling
R	Zipper cracks	3	Extrusion
S	Cold shut	4	Closed die forging
		5	Casting

• A. P-3; Q-1; R-2; S-4
• B. P-5; Q-2; R-3; S-4
• C. P-1; Q-2; R-4; S-5
• D. P-3; Q-1; R-2; S-5

Hint:

Match each defect to the process where it typically forms; remember cold shut can occur in both forging and casting.

Answer 1

The Correct Option is A, D

Step 1: List the four defects and think about where metal is stretched or pulled:
This is a matching type MSQ, so instead of matching one by one, group the processes by the kind of stress they put on the material.
Extrusion and wire drawing pull the metal through a die, creating tension at the core, that is what causes centerburst.
Deep drawing stretches a flat sheet into a cup shape, and this uneven stretching around the flange is what produces earing.
Rolling squeezes the strip between two rollers, and uneven elongation through the thickness produces zipper cracks.
Forging and casting both involve metal flowing and meeting itself, so cold shut can appear in either.

Step 2: Fix the three definite pairs first:
From the reasoning above, P (centerburst) always pairs with 3 (extrusion), Q (earing) always pairs with 1 (deep drawing), and R (zipper cracks) always pairs with 2 (rolling).
These three pairs, P-3, Q-1, R-2, appear in exactly the same form in options (A) and (D), so the answer must be one or both of these two options.

Step 3: Decide what S (cold shut) pairs with:
Cold shut is not tied to just one process. It happens whenever two flows of metal meet but do not fuse: in closed die forging (option A gives S-4) when the die closes before the flash fully joins, and in casting (option D gives S-5) when two streams of molten metal meet a fraction too late and freeze before bonding.
Since both situations genuinely produce a cold shut, both S-4 and S-5 are acceptable pairings.

Step 4: Reject the remaining options:
Option (B) breaks the fixed pairing by sending centerburst to casting and earing to rolling, so it is wrong.
Option (C) sends centerburst to deep drawing, which contradicts the definite pairing found in Step 2, so it is wrong too.

Final Answer:
Only the options that keep P-3, Q-1, R-2 fixed and use either S-4 or S-5 are correct. \[ \boxed{\text{(A) and (D)}} \]