A zinc crystal is strained to point A, unloaded, and then reloaded in the direction opposite to the original slip direction:What is the reason for the drop in shear stress when loaded in the opposite direction?

Increase in the number of slip system

A zinc crystal is strained to point A, unloaded, and then reloaded in

1.	A zinc crystal is strained to point A, unloaded, and then reloaded in the direction opposite to the original slip direction: What is the reason for the drop in shear stress when loaded in the opposite direction?
A.	n<a href="https://www.sanfoundry.com/wp-content/uploads/2020/01/mechanical-metallurgy-questions-answers-plastic-deformation-single-crystal-deformation-twinning-q4.png"><img alt="Find the reason for the drop in shear stress when loaded in the opposite direction" class="alignnone size-full wp-image-265621" height="302" sizes="(max-width: 532px) 100vw, 532px" src="https://www.sanfoundry.com/wp-content/uploads/2020/01/mechanical-metallurgy-questions-answers-plastic-deformation-single-crystal-deformation-twinning-q4.png" srcset="https://www.sanfoundry.com/wp-content/uploads/2020/01/mechanical-metallurgy-questions-answers-plastic-deformation-single-crystal-deformation-twinning-q4.png 532w, https://www.sanfoundry.com/wp-content/uploads/2020/01/mechanical-metallurgy-questions-answers-plastic-deformation-single-crystal-deformation-twinning-q4-300x170.png 300w" width="532"/></a>
B.	Back stress
C.	Strain hardening
D.	Increase in the number of slip system
E.	Slip plane reorientation
Answer» B. Back stress