A motor driving a solid circular shaft transmits 30 kW at 500 r.p.m. What is the torque activity on the shaft, if allowable shear stress is 42 MPa?

This question was previously asked in
ESE Civil 2021 Official Paper
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  1. 427 Nm
  2. 573 Nm
  3. 180 Nm
  4. 219 Nm

Answer (Detailed Solution Below)

Option 2 : 573 Nm
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Detailed Solution

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Concept:

Power (P)

P = T × W

Torsion equation

\(\frac{T}{J} = \frac{{G\theta }}{L} = \frac{\tau }{r}\)

Calculation:

Given:

P = 30 kW, N = 500 rpm, D = 40 mm

T = ?

As, P = T × W

\(30 \times {10^3} = {\rm{T}} \times \frac{{2{\rm{\pi }} \times 500}}{{60}} \)

T = 572.9 kN ≈ 573 N-m

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