Question

A torque of 10 Nm is transmitted through a stepped shaft as shown in figure. The torsional stiffness of individual sections of lengths MN, NO and OP are 20 Nm/rad 30 Nm/rad and 60 Nm/rad respectively. The angular deflection between the ends M and P of the shaft is

• A. 0.5 rad
• B. 1.0 rad
• C. 5.0 rad
• D. 10 rad

Answer 1

The correct option is B 1.0 rad

Here each shaft connected with each other in series. Torque is same in each part.
${\theta }_{MN}=\frac{T}{K_t}=\frac{10}{20}=0.5radian{\theta }_{NO}=\frac{10}{30}=\frac{1}{3}rad{\theta }_{OP}=\frac{10}{60}=\frac{1}{6}rad{\theta }_{MP}={\theta }_{MN}+{\theta }_{NO}+{\theta }_{OP}$

$=0.5+\frac{1}{3}+\frac{1}{6}$

$=1.0rad=1.0radian$