A helical torsion spring of mean diameter 60 mm is made of a round wire of 6 mm diameter. If a torque of 6 N-m is applied on the spring, find the bending stress induced and the angular deflection of the spring in degrees. The spring index is 10 and modulus of elasticity for the spring material is 200 kN/mm2 . The number of effective turns may be taken as 5.5.

bending stress = 305.577 MPa

angular deflection   = 28.011°

Explanation:

given data

mean diameter D = 60 mm = 0.6 m

wire diameter d = 6 mm = 6 × m

torque Mb = 6 N-m

spring index = 10

elasticity for the spring material = 200 kN/mm² = 200 ×   N/m²

number of effective turns = 5.5

solution

first we get here bending stress that is express as

    .....................1

here k is stress factor i.e 1.08 for round wire

put here value and we get

= 305.577 MPa

and

angular deflection will be here

angular deflection ∅ =     ............2

put here value and we get

angular deflection ∅ =    

angular deflection ∅  = 0.4889 radian  = 28.011°

the correct answer is c.stops after infancy and childhood.

myelin is the substance of the central nervous system (cns) that insulates nerve cell axons to increase the speed at which nerve impulse travels. myelination is a process of myelin formation. this process occurs postnatally, begins in the embryo during the midst of early development and finishes after birth.