Question

Calculate the twisting couple on a solid shaft of length 1.5 m and diameter 120 mm, when it is twisted through an angle 0.6 degree. The coefficient of rigidity for the material of the shaft may be taken to be 93 x 109 N/m^2

Answer 1

PLEASE MAKE ME BRAINLIST

Correct option is

B

0.64×10

−1

N/m

Radius of solid cylinder r

1

=4.9cm

Outer radius of Hollow cylinder R

2

=5cm

Inner radius of Hollow cylinder r

2

=4cm

Twisting Couple G=Cθ where C=

2l

πηr

4

∴ Twisting couple per unit twist =

θ

G

=C

Given: (G/θ)

1

=0.1N/m

θ

G

is proportional to r

4

.

Hence,

(G/θ)

2

(G/θ)

1

=

R

2

2

−r

2

2

r

1

2

Substituting the values in the above equation gives,

(G/θ)

2

=0.64×10

−1

N/m