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Railways PYQCBT 1 2016

RRB NTPC · Question 65

Which of the following is a wrong example of friction?

  1. Washing machine pushed along a floor

  2. Sled sliding across snow

  3. A person sliding down a slide

  4. A person lifting an heavy object

Show answer & explanation

Answer: (D) A person lifting an heavy object

Explanation

Friction acts when surfaces slide against each other: a washing machine pushed on a floor, a sled on snow and a person on a slide all involve it. Lifting a heavy object straight up is working against gravity, not friction, so it is the wrong example.