Grade 8 Friction Revision-2

1) Which device is used to reduce friction in the axles of cars and shafts of electric motors

• screws
• ball bearings
• nuts
• bolts

2) Which one produces maximum friction

• rubbing sand paper on butter paper
• rubbing sand paper on glass top table
• rubbing sand paper on aluminium
• rubbing sand paper on sand paper

3) Which produces the least friction

• A box sliding down a slope
• box with wheels rolling down
• stationary box
• box sliding on a horizontal surface

4) Friction on a wooden table can be reduced by

• polishing it
• rubbing oil on it
• putting a glass table on top
• all of the above

5) People usually tend to ____________on wet floor.

• run fast
• stand still
• slip
• none of these

6) Rolling friction is more than the sliding friction

• True
• False

7) Friction always works in the direction of motion of the objects

• True
• False

8) Magnitude of fluid friction depends upon the nature of the fluid

• True
• False

9) More streamlined the shape of an object, greater is fluid friction

• True
• False

10) Friction produces heat

• True
• False