Online Test — Friction
25 Questions • 15 min • Chapter MCQ
15:00
Question 1 of 25
Friction is a force that:
Helps motion
Opposes relative motion
Has no direction
Increases speed
Explanation: Friction opposes the relative motion between two surfaces in contact.
Question 2 of 25
Friction is mainly caused by the ______ of surfaces.
Colour
Roughness
Temperature
Weight
Explanation: Friction is caused by the roughness (tiny bumps) of surfaces.
Question 3 of 25
The friction acting on an object that is sliding over a surface is:
Static friction
Sliding friction
Rolling friction
No friction
Explanation: Sliding (kinetic) friction acts when an object slides over a surface.
Question 4 of 25
Which type of friction is the smallest?
Static
Sliding
Rolling
All equal
Explanation: Rolling friction is the smallest of the three types.
Question 5 of 25
The correct order of friction from greatest to least is:
Rolling > sliding > static
Static > sliding > rolling
Sliding > static > rolling
Static > rolling > sliding
Explanation: The order is static > sliding > rolling friction.
Question 6 of 25
Friction between two surfaces depends mainly on their nature and the force:
Of gravity only
Pressing them together
Of the wind
Of the sun
Explanation: Friction depends on the surfaces' roughness and the force pressing them together.
Question 7 of 25
Rougher surfaces generally produce ______ friction.
Less
More
No
Zero
Explanation: Rougher surfaces have more bumps that interlock, producing more friction.
Question 8 of 25
A heavier object on a surface experiences ______ friction than a lighter one.
Less
More
The same
No
Explanation: A heavier object presses harder on the surface, so it experiences more friction.
Question 9 of 25
Polishing a surface usually ______ the friction.
Increases
Decreases
Doubles
Has no effect on
Explanation: Polishing makes a surface smoother, which decreases friction.
Question 10 of 25
For ordinary surfaces, the area of contact has ______ effect on friction.
A very large
Little
The greatest
An infinite
Explanation: For ordinary surfaces, the contact area has little effect on friction.
Question 11 of 25
Friction between our shoes and the ground allows us to:
Fly
Walk without slipping
Float
Swim
Explanation: Friction lets us walk by gripping the ground and preventing slipping.
Question 12 of 25
We tend to slip on a wet floor because it has:
Too much friction
Very little friction
No surface
High pressure
Explanation: A wet floor is smooth with very little friction, so we slip.
Question 13 of 25
Friction makes writing possible because it lets a pencil:
Float above paper
Leave marks on paper
Melt
Stay dry
Explanation: Friction between pencil and paper rubs off graphite to leave marks.
Question 14 of 25
Grooves and treads on tyres are used to:
Reduce friction
Increase friction (grip)
Remove the tyre
Add weight
Explanation: Treads increase friction (grip) with the road, preventing slipping.
Question 15 of 25
Spreading sand on an icy road helps by:
Reducing friction
Increasing friction
Melting the ice instantly
Removing the road
Explanation: Sand makes the road rougher, increasing friction so vehicles do not skid.
Question 16 of 25
Which of these is a disadvantage of friction?
It lets us walk
It causes wear and tear
It helps braking
It helps writing
Explanation: Friction wears away rubbing surfaces, causing wear and tear.
Question 17 of 25
Friction between rubbing surfaces produces:
Light only
Heat
Sound only
Electricity
Explanation: Friction between rubbing surfaces produces heat.
Question 18 of 25
Applying oil or grease between surfaces to reduce friction is called:
Streamlining
Lubrication
Polishing
Welding
Explanation: Lubrication uses oil or grease to form a slippery layer, reducing friction.
Question 19 of 25
Ball bearings reduce friction by changing sliding friction into:
Static friction
Rolling friction
More sliding friction
Heat
Explanation: Ball bearings replace sliding with the smaller rolling friction.
Question 20 of 25
Giving a vehicle a smooth, tapered shape to reduce fluid friction is called:
Lubrication
Streamlining
Polishing
Braking
Explanation: Streamlining reduces fluid friction (drag) for easier movement.
Question 21 of 25
The resistance a fluid offers to an object moving through it is called:
Static friction
Fluid friction (drag)
Rolling friction
Pressure
Explanation: Fluid friction (drag) is the resistance a fluid offers to a moving object.
Question 22 of 25
As the speed of an object through a fluid increases, the drag on it:
Decreases
Increases
Stays the same
Becomes zero
Explanation: Fluid friction (drag) increases as the object moves faster.
Question 23 of 25
Giving an object a smooth, tapered shape to reduce drag is called:
Lubrication
Streamlining
Polishing
Braking
Explanation: Streamlining reduces fluid friction by letting the fluid flow smoothly around the object.
Question 24 of 25
Aeroplanes and fast trains are streamlined mainly to:
Increase drag
Reduce fluid friction (drag)
Add weight
Increase friction with rails
Explanation: Streamlining reduces drag so they move faster and use less fuel.
Question 25 of 25
Which of these is a naturally streamlined animal?
Elephant
Fish
Hippopotamus
Tortoise
Explanation: A fish has a smooth, tapered (streamlined) body to glide through water.