Question

Fig, shows a system of four pulleys. The upper two pulleys are fixed and the lower two are movable. How are load and effort of the pulley system related?

• A. load $=8\times$ effort
• B. load $=$ effort
• C. load $=2\times$ effort
• D. load $=4\times$ effort

Answer 1

Answer: (D)

load $=4\times$ effort

Here it is 4 pulley system hence total load on tackle(movable part) will be equals to "$4T$"
and on block(fixed part) total effort will be "$T$"
Hence mechanical advantage(M.E)=$\frac{load}{effort}$=$\frac{4T}{T}$ =$4$
Therefore LOAD=4$\times$EFFORT