Mains power supplies are designed with very low internal resistance so that:

  1. they produce no current
  2. the voltage stays nearly constant as the load changes
  3. they get hot
  4. they are safer to touch
Answer

B) the voltage stays nearly constant as the load changes

Good regulation. SLO P-09-E-26 · Understanding

Physics MCQ · More Current Electricity MCQs · Practise