Question

A closely coiled helical spring of round steel wire 5 mm in diameter having 12 complete coils of 50 mm mean diameter is subjected to an axial load of 100 N. Modulus of Rigidity of the spring is $80kN/m{m}^2$. What is the deflection of the spring?

• A. 12 mm
• B. 24 mm
• C. 36 mm
• D. 48 mm

Answer 1

The correct option is B 24 mm

$\because \Delta =\frac{64P{R}^{3}n}{G{d}^4}$

$\therefore \Delta =\frac{64\times 100\times {\left(\frac{50}{2}\right)}^3\times 12}{80\times {10}^3\times 5^4}$

= 24 mm