# Multiple Movable Pulley

## Trending Questions

**Q.**

Draw a diagram of combination of three movable pulleys and one fixed pulley to lift up a load. In the diagram, show the directions of load, effort and tensiom in each strand. Find : (i) the mechanical advantage , (ii) the velocity ratio, and (iii) the efficiency of the combination, in the ideal situation.

**Q.**

A pulley system has a velocity ratio of 4 and an efficiency of 90 %. The effort required to raise a load of 300 N by the system is

83.33N

500.22N

75.66N

90.88N

**Q.**

In operating a water pump a resistance of 480 N Is overcome by an effort of 72 N. If the distance of the fulcrum from the point where resistance acts is 0.2 m find the distance from the fulcrum, where effort is applied.

**Q.**

The diagram alongside shows an arrangement of three pulleys A, B and C. The load is marked as L and the effort as E.

(a) Name the pulleys A, B and C.

(b) Mark in the diagram the directions of load (L) effort (E) and tension T1 and T2 in the two strings.

(c) How are the magnitudes of L and E related to the tension T1?

(d) Calculate the mechanical advantage and velocity ratio of the arrangement.

(e) What assumptions have you made in parts (c) and (d)?

**Q.**

According to the “law of levers”, $load\times loadarm=effort\times effortarm$.

- True
- False

**Q.**

The figure shows a diagram of a system of four pulleys. The upper two pulleys are fixed and the lower two are movable. What are the mechanical advantage and velocity ratio of the system?

M.A. = 5

M.A = 2

V.R = 2

V.R = 4

**Q.**

Define the term Lever

**Q.**

**A ****system of ****pulleys is ****used ****t****o ****lif****t ****a ****load ****of **$1000k{g}_{wt}$**. ****If the ****efficiency ****of ****t****he ****pul****l****ey ****system is **$80\%$** and veloc****i****ty ****r****atio ****i****s **$20$**, find the effort required to lift the load.**

**Q.**

A pulley system has velocity ratio of 3. If it efficiency is 75%, calculate the distance by which the load is raised, if the effort pulls in 12 m of rope.

4 m

36 m

5 m

3 m

**Q.**

The SI unit of a work is Newton

- True
- False

**Q.**

A fulcrum divides a crowbar in the ratio $3:1$. What weight will be lifted if an effort of $100\mathrm{N}$ is applied at the end of its long arm?

$400\mathrm{N}$

$100\mathrm{N}$

$300\mathrm{N}$

$500\mathrm{N}$

**Q.**A block and tackle system has 5 pulleys. If an effort of 1000N is needed in the downward direction to raise a load of 4500N. Calculate the efficiency of the system.

- 50%
- 60%
- 90%
- 80%

**Q.**

What happens when mechanical advantage (MA) becomes equal to one?

**Q.**

A pulley system can lift a load of 1200 N by an effort of 250 N. If the resistance due to the weight of movable parts and friction is 300 N. Find the total number of pulleys in the system.

2

4

6

8

**Q.**

A boy uses a single movable pulley to lift a load of $50\mathrm{kgf}$ to some height. Another boy uses a single fixed pulley to lift the same load to the same height. The ratio of efforts on single movable pulley to efforts on single fixed pulley is,

$2$

$1$

$\frac{1}{2}$

$4$

**Q.**

State the usefulness of such a machine whose mechanical advantage is less than $1$.

**Q.**A pulley system has a single fixed pulley and a single movable pulley. Find out its mechanical advantage.

- 1
- 2
- 3
- 4

**Q.**A type of single pulley is very often used as a machine even though it does not give any gain in mechanical advantage.

(i) Name the type of pulley used.

(ii) For what purpose is such a pulley used?

**Q.**

A ________ has length and width, but no height, and extends infinitely on all sides.

**Q.**Fig 3.40 shows a block and tackle system of pulleys used to lift a load.

What is the mechanical advantage of the system ?

**Q.**A block and tackle system has a velocity ratio of 4. If a man can exert a pull of 240 kgf, what is the maximum load he can raise with this pulley system if its efficiency is 80%? Also, determine the number of pulleys used in the system.

- 768 kgf;4
- 480 kgf;5
- 112 kgf;6
- 960 kgf;4

**Q.**A block and tackle system has 5 pulleys. If an effort of 1000N is needed in the downward direction to raise a load of 4500N. What is the mechanical advantage ?

- 4.5
- 2
- 3.5
- 5

**Q.**Draw a diagram to show a block and tackle pulley system having a velocity ratio of 3 marking the direction of load(L), effort(E) and tension(T).

**Q.**what is the velocity ratio of the pulley?

**Q.**

- True
- False

**Q.**

A block and tackle system has 5 pulleys and is 90% efficient. If the effort required to lift a load is 1000 N, find the effort required.

2000 N

100 N

111.1 N

155.5 N

**Q.**A lever has a mechanical advantage of 10. What load is newtons, can be moved by an effort of 6 newtons.

**Q.**The given combination of pulleys is used to lift a load of 2000 N. Find the distance traveled by the pulley B if the effort moves by 1 m.

- 0.10 m
- 0.25 m
- 0.50 m
- 0.60 m

**Q.**In the system of pulleys shown what should be value of m1 such that 100 gm remains at rest : (Take g=10m/s2)

- 180gm
- 100gm
- 160gm
- 200gm

**Q.**A fixed and movable pulley system has 50% efficiency. Find the velocity ratio of the system.

- 24
- 22
- 25
- 23