Question

Two different $\mathbf{12}\mathbf{-}\mathbf{V}$automobile batteries on a store shelf are rated at $\mathbf{600}$and $\mathbf{850}$“cold cranking amps.” Which has the smallest internal resistance?

Short answer

$850$the rated battery will have the smallest resistance.

Step-by-step solution

Step 1:Definition of internal resistance.

Internal resistance is opposition to the flow of current by batteries which generate heat.

Step 2:Finding battery with less internal resistance

For the same voltage, the battery having a larger current rating (this is what cold-cranking amps indicate) has lower resistance $\mathrm{I}$and $\mathrm{R}$are inversely related via Ohm's law. Hence $850$rating will have the smallest internal resistance.