The particles in a ferrofluid are coated with a surfactant to:

  1. make them magnetic
  2. change their colour
  3. stop them clumping together
  4. make them heavier
Answer

C) stop them clumping together

Keeps them suspended. SLO P-09-E-09 · Understanding

Physics MCQ · More Magnetism and Electromagnetic Induction MCQs · Practise