Q. Which of the following is/are correctly matched?

1. Static friction -self-adjusting force
2. Sliding friction- less than limiting friction
3. Rolling friction -greater than sliding friction

Select the correct answer from the codes given below:
Answer: Only 1 and 2
Notes: Friction is self-adjusting force. When the applied force is gradually increased the force of friction also increases at the same rate and body remains stationary. This force of friction is called force of static friction. The force of friction between the two surfaces in contact with one of them just over the other is called sliding friction. It is less than the limiting static friction. The force of friction between the two surfaces in contact with one of them rolling over the other is called the rolling friction. It is much smaller than sliding friction.