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 8% respectively. The velocity of the lower jaw is 0.50 cm/s.
Question 75 (Textile Engineering & Fibre Science)
The time required to break the sample in seconds is
| (A) | 3.7 |
| (B) | 4.3 |
| (C) | 5.2 |
| (D) | 6.3 |
[Show Answer]
Option A 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=8%
i.e ,
Breaking extension=gauge length x 8%
Breaking extension(e)=20 x 8/100
Breaking extension(e)=1.6 cm
The velocity of lower jaw(v)=0.50 cm/s
Pendulum swings by=30 deg from its normal position
Time require to break the sample(t)=?
By formula-
Time(t)=3.7 sec (Ans)