In the calculation of induced shear stress in helical springs, the Wahl’s stress factor is used to take care of

combined effect of transverse shear stress and bending stress in the wire
combined effect of bending stress and curvature of the wire
combined effect of transverse shear stress and curvature of wire
combined effect of tor
✅ The correct answer is option B.

A compound cylinder with inner radius 50 mm and outer radius 70 mm is made by shrinking one cylinder on to the other cylinder, The junction radius is 60 mm and the junction pressure is 1.1 N/mm2. The maximum hoop stress developed in the inner cylinder is

3.6 N/mm2 compression
3.6 N/mm2 tension
7.2 N/mm2 compression
7.2 N/mm2 tension
✅ The correct answer is option C.