Same chapter4 marksDifficulty: Hard
A machine has a velocity ratio of 6 and an efficiency of 80%. Calculate the mechanical advantage and the effort needed to raise a load of 480 N.
Machines
4 marksDifficulty: Hard
A block and tackle system has 4 pulleys. If the efficiency is 75%, calculate the effort needed to raise a load of 900 N.
Original Khojo Papers practice question — not from a past board paper.
Answer
300 N
No citable source has been recorded for this record. Treat it as practice material, not as fact.
Explanation
The velocity ratio is 4, so the mechanical advantage is 0.75 × 4 = 3 and the effort is 900 ÷ 3 = 300 N.
Related questions
From the same topic and chapter, at a similar level.
Same chapter2 marksDifficulty: Easy
Define mechanical advantage, velocity ratio and efficiency of a machine.
Machines
Same chapter3 marksDifficulty: Medium
Why is the efficiency of a practical machine always less than 100%?
Machines
Same chapter3 marksDifficulty: Medium
A machine raises a load of 300 N with an effort of 100 N. Calculate its mechanical advantage.
Machines
Same chapter3 marksDifficulty: Medium
In a machine the effort moves 5 m while the load moves 1 m. Calculate the velocity ratio.
Machines
Same chapter3 marksDifficulty: Medium
State the velocity ratio of a single fixed pulley and of a single movable pulley, and give one use of each.
Machines