Final answer:
The strain of the specimen is 0.0012 inches/inch.
Step-by-step explanation:
The tensile strain of a material is defined as the change in length divided by the original length. In this case, the specimen elongates 0.0024 inches between two punch marks that are initially two inches apart. Therefore, the strain is calculated as:
Strain = Change in length / Original length
Strain = 0.0024 inches / 2 inches = 0.0012 inches/inch
So, the correct answer is (a) 0.0012.