When a closely coiled helical spring is subjected to a couple about its axis, the stress induced in the wire material of the spring is
A. Bending stress only
B. A combination of torsional shear stress and bending
C. Direct shear stress only
D. A combination of bending stress and direct shear stress
Answer: Option A

Bending stress only
if couple supjected about the axis the shear will zero act in opposite direction
if couple supjected about the axis the shear will zero act in opposite direction