Question

Which class of lever has the mechanical advantage always less than 1? Give an example.

Answer 1

The mechanical advantage of lever is equal to the ratio of effort arm to the load arm.
𝑀𝑒𝑐ℎ𝑎𝑛𝑖𝑐𝑎𝑙 𝑎𝑑𝑣𝑎𝑛𝑡𝑎𝑔𝑒 𝑜𝑓 𝑙𝑒𝑣𝑒𝑟

$=\frac{Effortarm}{Loadarm}$
For, 𝑀.𝐴. < 1
𝐸𝑓𝑓𝑜𝑟𝑡 𝑎𝑟𝑚 < 𝐿𝑜𝑎𝑑 𝑎𝑟𝑚
In class III levers the fulcrum is at one end and the effort is closer to the fulcrum. Thus the effort arm is always shorter than the load arm hence the mechanical advantage of class III lever is always less than 1.