1. In a tensile test of ductile material, necking starts at
2. A metallic sheet 1 m wide and 10 mm thick is to be rolled under a front tension force of 100 KN. A specimen from the sheet, tested under tension, shows a yield stress of 100 MPa. Assume plain strain condition during rolling and ignore the friction. If yielding is assumed to start at a roll pressure of σ3 MPa, then the stress in the width direction (where strain is zero) is
3. Match the forming methods in Group 1 with the defects in Group 2.
Group 1
Group 2
P. Extrusion
1. Flash cracking
Q. Closed die forging
2. Fir-tree cracking
R. Rolling
3. Alligatoring
4. Earing
| Group 1 | Group 2 |
| P. Extrusion | 1. Flash cracking |
| Q. Closed die forging | 2. Fir-tree cracking |
| R. Rolling | 3. Alligatoring |
| 4. Earing |
4. The maximum axial compression stress during cold upsetting of a cylindrical rod of radius, 'r', occurs at
5. The defects that are not observed in extruded products are
P. Chevron cracking
Q. Fold
R. Piping
S. Surface cracking
T. Alligatoring
P. Chevron cracking
Q. Fold
R. Piping
S. Surface cracking
T. Alligatoring
6. Which of the following metal forming techniques is used to produce soft drink cans from aluminium sheets?
7. Match the defects listed in Group I with the corresponding manufacturing process listed in Group II.
Group I
Group II
P. Orange-peel effect
1. Extrusion
Q. Chevron cracking
2. Deep drawing
R. Flash
3. Arc welding
S. Undercut
4. Forging
| Group I | Group II |
| P. Orange-peel effect | 1. Extrusion |
| Q. Chevron cracking | 2. Deep drawing |
| R. Flash | 3. Arc welding |
| S. Undercut | 4. Forging |