Question

The diameter of shaft A is thrice that of the diameter of shaft B. Power transmitted by shaft A when compared to shaft B will be

• A. 3 times
• B. 9 times
• C. 27 times
• D. 81 times

Answer 1

Answer:

C. 27 times

Given: $D_A =3 D_B$' Power ∝ Torque, And Torque, $T = \frac {\tau_{max} \times \pi\times D^ 3} {16} .: Power (P) \propto D ^ 3 \Rightarrow \frac{P_{A}}{P_{B}} = (\frac{d_{A}}{d_{B}}) ^ 3 = (\frac{3d_{B}}{d_{B}}) ^ 3 = (3) ^ 3 = 27$