FRACTURES SET 06

FRACTURES SET 06

1. What doesn’t favor a brittle fracture?
a) Tri-axial state of stress
b) A low temperature
c) High strain rate
d) Slow rate of loading

Answer: d

2. In a Charpy test, high hammer velocity ensures ______
a) High strain rate
b) Local stresses
c) Ductility in fracture
d) Low stress concentration

Answer: a

3. A crack will propagate if the decrease in _____ is at least equal to the energy required to create the new crack surface.
a) Plastic energy
b) Elastic energy
c) Toughness
d) Resilience

Answer: b

4. Automobile crankshaft is likely to undergo _____ fracture.
a) Ductile
b) Brittle
c) Intergranular
d) Fatigue

Answer: d

5. Strain energy required in a ductile fracture is ____ and _____ in brittle.
a) Higher, higher
b) Higher, lower
c) Lower, higher
d) Lower, lower

Answer: b

6. How does fracture surface appear in brittle fracture?
a) Rough and dull
b) Smooth and bright
c) Cup and cone
d) Fibrous

Answer: b

7. Ductile fractured surface appears _____
a) Dull
b) Smooth
c) Bright
d) Flat

Answer: a

8. Stress during cracking _____ in ductile fracture and _____ in brittle.
a) Increases, increases
b) Increases, decreases
c) Increases, constant
d) Decreases, decreases

Answer: c

9. All metals fracture in a ductile manner.
a) True
b) False

Answer: b

10. Little deformation takes place in brittle fracture.
a) True
b) False

Answer: a