Class 3 Lever

Q.

State the class of levers and the relative positions of load (L), effort (E) and fulcrum (F) in (a) a bottle opener, and (b) sugar tongs.

Q.

State the kind of lever which always has the mechanical advantage less than 1. Draw a labelled diagram of such a lever.

Q.

The lever for which the mechanical advantage is less than 1 has the :

(a) fulcrum at the midpoint between the load and effort.

(b) load between the effort and fulcrum.

(c) the effort between the fulcrum and load.

(d) load and effort acting at the same point.

Q.

Class III levers have the mechanial advantage less than 1. Why are they then used ?

Q. Class 1 lever has fulcrum in between the load and effort.

1. False
2. True

Q.

The force that has to be overcome by the machine is called load.

1. True
2. False

Q.

What is the principle of a lever? Write an expression for its mechanical advantage.

Q.

Define the mechanical advantage of a machine

Q.

Give one word for this-

The point about which a lever can turn

Q. What is the mechanical advantage of a lever if a load of 80 N is moved by an effort of 20 N?

Q. Pick the lever that acts as a speed multiplier from the following:

1. Scissors
2. Broomstick
3. Nutcracker
4. Wheelbarrow

Q.

Explain why the mechanical advantage of the class III lever is always less than 1.

Q.

Class III levers have mechanical advantage less than one. Why are they then used?

1. To obtain gain in speed

2. To obtain loss in speed

3. It acts as force multiplier

4. It is used in raising a load

Q.

Draw a labelled sketch of a class III lever. Give one example of this kind of lever.

Q. Which of the following is not a class III lever?

1. Human arm
2. Fire tongs
3. Knife
4. Seesaw

Q.

Define Fulcrum

Q.

State the kind of lever which always has the mechanical advantage less than 1.

1. LEVER I

2. LEVER III

3. LEVER II

4. Both B and C

Q.

Which one of the options represents the mathematical expression for the mechanical advantages of the lever shown below?

1. FE/FL

2. FE+FL

3. FLxFE

Q.

Examine the figure shown below and answer the question that follows.

Given $FL=2m$ and $LE=1m$, calculate the mechanical advantage of the lever as shown above.