How quickly is the electric field established throughout a circuit?

Question

Accepted Answer

A. Almost instantly

1. Drift speed itself is only millimetres per second.
2. Yet a lamp lights the moment the switch closes.
3. Electric field is established throughout the circuit almost instantly, with the speed of light.
4. So the answer is almost instantly.
_Source: syllabus Physics, Ch 3 'Current Electricity'_

Answer

Almost invisibly

Answer

Almost identically

Answer

Almost incorrectly

How quickly is the electric field established throughout a circuit?

Keep practising Current Electricity