Class 8 Science
Multiple Choice Questions
Question 1: Which of the following uses spikes in shoes?
- Rugby player
Answer: (c) Rugby player
Question 2: Mobil oil is used in scooters and bikes for which purpose?
- As fuel
- For reducing friction
- For increasing friction
- None of the above
Answer: (b) For reducing friction
Question 3: Tyres of which vehicles are biggest treads among the following?
- Race car
Answer: (d) Excavator
Question 4: Which of the following is used in powdered form as lubricant?
Answer: (a) Graphite
Question 5: Increasing friction is necessary for which of the following?
- Free wheel of bicycle
- Bicycle handle bar
- Chain of bicycle
- Ball bearing in front wheel
Answer: (b) Bicycle handle bar
Question 6: Which of the following surfaces will offer the least friction?
- Vinyl floor
Answer: (d) Ice
Question 7: Least amount of friction is required in which of the following sports?
- Car Race
- Ice Skating
- Tug of war
Answer: (c) Ice Skating
Very Short Answer Type Questions
Question 1: What is friction?
Answer: The force created due to relative movement between two surfaces is called friction.
Question 2: What is static friction?
Answer: The minimum amount of force that is required to overcome the force of friction is called static friction.
Question 3: What is sliding friction?
Answer: Once an object starts moving on a surface, some force is required to keep the object moving. The minimum force that is required to keep a moving object in motion at a constant speed is called sliding friction.
Question 4: What is rolling friction?
Answer: When an object rolls over a surface, the friction created is called rolling friction.
Question 5: Arrange different types of friction in descending order?
Answer: Static friction > Sliding friction > Rolling friction
Question 6: What is fluid friction?
Answer: Friction due to a fluid is called fluid friction or drag.
Question 7: What is a streamlined shape?
Answer: A shape which is wide in middle and tapered at ends is called a streamlined shape.