In a block and tackle pulley system with n supporting strings, the ideal mechanical advantage is:
An + 1
Bn
C2n
Dn / 2
Answer & Solution
Correct answer: B. n
1. The load hangs from the lower (movable) block.
2. n strings each support an equal share of the load.
3. Each carries load / n in tension.
4. So the effort applied to one end equals load / n.
5. M.A. = load / effort = n.
_Source: Selina Concise Physics ICSE Class 10, Ch 3 'Machines' (aplustopper.com extract)_
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