Topic: Theory of Machines
The ratio of the height of a porter governor (when the length of arms and links are equal) to the height of watt governor is: (m: mass of the ball; M: mass of the sleeve)
- A. $\frac{m}{m+M}$
- B. $\frac{M}{m+M}$
- C. $\frac{m+M}{m}$
- D. $\frac{m+M}{M}$
Answer: C. $\frac{m+M}{m}$
Explanation: The height of a Porter governor is $h_{porter} = \frac{895}{N^{2}}(\frac{m+M}{m})$ and the height of a Watt governor is $h_{watt} = \frac{895}{N^{2}}$. Thus, the ratio $\frac{h_{porter}}{h_{watt}} = \frac{m+M}{m}$.