Question

The angle of twist of a closely helical spring under an axial torque is given by :

• A. $\frac{64Tdn}{G{D}^4}$
• B. $\frac{32Tdn}{G{D}^4}$
• C. $\frac{32TDn}{G{d}^4}$
• D. $\frac{64TDn}{G{d}^4}$

Answer 1

The correct option is C $\frac{32TDn}{G{d}^4}$

Angle of twisting in closed helical spring

$\theta =\frac{TL}{GJ}=\frac{32T\times 2\pi Rn}{G\pi d^4}$

$\theta =\frac{32TDn}{G{d}^4}=\frac{64P{R}^{2}n}{G{d}^4}$