Red Seal Electrician Practice
Safety and work practicesQuestion 600 of 1506

A worker grasps a metal pipe with both hands instead of one hand. How does the contact resistance change, other factors being equal?

  1. It is about double, because two hands add more skin area.
  2. It does not change, because the pipe is still the same pipe in both cases.
  3. It is about half, because the contact area is twice as large.
  4. It is zero, because two hands always act as a short circuit.
Show answer

Correct answer: It is about half, because the contact area is twice as large.

Resistance falls as contact area grows. Two contact areas act as two parallel paths.

Source: Lessons in Electric Circuits I: DC (Kuphaldt), 3.4: Ohm’s Law (again)

Practice safety and work practices

Questions last reviewed: 18 October 2026