Common Data Questions
Assume that the “standard machine rate of loading” of a commercial tensile testing machine working on pendulum lever principle is 200 kgf/cm. The breaking load and extension of a sample tested at a gauge length of 20 cm is 50 kgf and 80% respectively. The velocity of the lower jaw is 0.50 cm/s.
Question 74 (Textile Engineering & Fibre Science)
The change in “machine rate of load” (kgf/cm) as pendulum lever swings by 30 degrees from its normal position, is
| (A) | 100 |
| (B) | 173.2 |
| (C) | 346.4 |
| (D) | 400 |
[Show Answer]
Option B is correct.
Given in the question-
Standard machine rate of loading(
)=200 kgf/cm
Gauge length=20 cm
The breaking load(F)=50 kgf
Breaking extension(e)=8%
The velocity of lower jaw(v)=0.50 cm/s
Pendulum swings by=30 deg from its normal position
The change in machine rate of loading(
)=? in kgf/cm
By formula-
Where, 
is the pendulum swings angle
kgf/cm
i.e.,
The change in machine rate of loading=173.2 kgf/cm (Ans)