Question

In a spring-controlled governor, the controlling force curve is a straight line. Balls are 500 mm apart when the controlling force is 1800 N and they are 300 mm apart when the force is 1000 N. To make the governor isochronous initial tension must be decreased by

• A. - 800 N
• B. - 550 N
• C. 550 N
• D. - 200 N

Answer 1

The correct option is D - 200 N

$F=c_{1}r+c_2$

$1800=c_1\left(0.5\right)+c_2....\left(1\right)$

$1000=c_1\left(0.3\right)+c_2....\left(2\right)$

By eq (1)- eq(2)

$0.2c_1=800$

$\Rightarrow c_1=4000$

$c_2=1800-4000\left(0.5\right)\Rightarrow c_2=-200N$

So initial tension must be increased by 200 N to be isochronous