science simple machine grade 7

A string roller is an example of

• pulley

• third class lever

• wheel and axle

• second class lever

which of the following machine is inclned plane wrapped on a cylinder?

• wedge

• inclined plane

• pulley

• screw

A staircase is an example of:

• third class lever

• incline plane

• second class lever

• first class lever

What type of lever cannot magnify the applied effort?

• first class lever

• second class lever

• third class lever

• all of the above

Which of the following machine has co-axial cylinder

• inclined plane

• wedge

• pulley

• wheel and axle

The formula for principle of lever is:

• E x Ed= Lx Ld

• E x L= Ed x Ld

• E x Ld = L x Ed

• E/L = Ed/Ld

A simple machine that has a disc with a grooved rim to wind up a string is called

• wedge

• incline plane

• pulley

• wheel and axle

nut cracker is an example of

• 1st class lever

• 3rd class lever

• 2nd class lever

• wheel and axle