HARD

Earn 100

The diagram shows a fixed pulley used by a boy to lift a load of $500 N$ through a vertical height. The effort applied by the boy on the other end of the rope is $630 N$ . Calculate the efficiency of the pulley.

Important Questions on Simple Machine

EASY

The diagram below shows a claw hammer used to remove a nail:

Question Image

(i) To which class of lever does it belong?
(ii) Give one more example of the same class of lever mentioned by you in (i) for which the mechanical advantage is greater than one.

HARD

Science>Physics>Simple Machine>Pulley

The diagram below shows a pulley arrangement:

Question Image

Copy the diagram and mark the direction of tension on each stand of the string.
What is the velocity ratio of the arrangement?
If the tension acting on the string is $T$ , then what is the relationship between $T$ and effort $E$ ?
If the free end of the string moves through a distance $x$ , find the distance by which the load is raised.

MEDIUM

Science>Physics>Simple Machine>Pulley

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

T_{1}

and

T_{2}

in the two strings.
(c) How are the magnitudes of

L

and

E

related to the tension

T_{1}

?
(d) Calculate the mechanical advantage and velocity ratio of the arrangement.
(e) What assumptions have you made in parts (c) and (d)?
Question Image

EASY

Science>Physics>Simple Machine>Pulley

Explain why the mechanical advantage of a

Class II

type of lever is always more than one.

MEDIUM

Science>Physics>Simple Machine>Pulley

A man uses a crowbar of length

1.5 m

to raise a load of

75 kgf

by putting a sharp edge below the bar at a distance

1 m

from his hand. Draw a diagram of the arrangement showing the fulcrum (F), load (L) and effort (E) with their directions. State the kind of lever. Calculate: (i) load arm, (ii) effort arm, (iii) mechanical advantage and (iv) the effort needed.

EASY

Science>Physics>Simple Machine>Pulley

Give reason for the following:
In a single fixed pulley, the velocity ratio is always more than the mechanical advantage.

EASY

Science>Physics>Simple Machine>Pulley

Explain why the mechanical advantage of the

class III

type of lever is always less than

1

EASY

Science>Physics>Simple Machine>Pulley

Name the pulley which has no gain in mechanical advantage. Explain, why is such a pulley then used?

EASY

Science>Physics>Simple Machine>Pulley

Draw a labelled sketch of a

class III

lever. Give one example of this kind of lever.

MEDIUM

Science>Physics>Simple Machine>Pulley

Draw Diagrams to illustrate the position of fulcrum load and effort, in the following:
Forceps .

MEDIUM

Science>Physics>Simple Machine>Pulley

Draw a diagram of a lever which is always used as a force multiplier. How is the effort arm related to the load arm in such a lever?

MEDIUM

Science>Physics>Simple Machine>Pulley

State the class of levers and the relative positions of load (

L

) effort (

E

) and fulcrum (

F

) in sugar tongs .

EASY

Science>Physics>Simple Machine>Pulley

Name the three classes of levers and distinguish between them. Give two examples of each class.

EASY

Science>Physics>Simple Machine>Pulley

Classify the following into lever as class I, class II or class III: a wheel barrow.

MEDIUM

Science>Physics>Simple Machine>Pulley

The diagram below shows a pulley arrangement.
(a) In the diagram, mark the direction of tension on each strand of string.
(b) What is the purpose of the pulley