The discussion revolves around the scenario of a 12V car battery being shorted momentarily, with a focus on understanding the implications of internal resistance and current flow in such a situation.
There is active engagement with the topic, with participants sharing their understanding and calculations. Some guidance is offered regarding the dangers of shorting a battery and the relationship between voltage, resistance, and current. Multiple interpretations of the term "short" are being explored.
Participants note the potential hazards associated with shorting a car battery, including the risk of explosion, and discuss the implications of internal resistance in the context of circuit behavior.
cepheid said:I hear that one should not try to short a car battery (connect the + and - terminals directly with a wire of negligible resistance) because they have a tendency to explode. This is because in circuit loop of such paltry resistance, the current drawn will be HUGE. Think about it...the battery supplies an EMF of 12V. There has to be a corresponding (and equal) potential drop around the circuit. The only resistance available to provide such a voltage drop is the internal resistance of the battery, because the potential drop is given by V = RI. So 12V = RI ==> I = 12V/.4Ohm = 30 A. Did I get this right?