Circuit misconceptions

Jacobs Physics blog bring us a post about Circuit Misconceptions

Circuit misconceptions, and an advance copy of a quiz: 

On a problem set last week, I gave students the simple circuit shown to the right. I asked what would happen to various parts of the circuit when I decreased R₂. One of the questions in particular said, "What will happen to the current flowing from the battery when the value of R₂ is decreased?"

The most common answer:

"The current will not change, because it's the same battery, so it will always provide the same current."

Silly students, a battery provides a constant VOLTAGE, not a constant current -- but that's a common misconception in the first week of circuits.

The second most common answer:

"The current will not change, because R₂ is the farthest resistor from the battery, and so the current hasn't reached R₂ yet.

(click here to read entire article and see how Mr. Jacobs solve the students' misconception)

More:
Parallel resistors misconceptions.
Circuits.