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A resistance coil is connected to a battery. In which arrangement will the maximum heat be produced?

1. When the coil is connected directly across the battery
2. When the coil is split into two equal sections and the two sections are joined in parallel across the battery
3. When the coil is split into four equal sections and all four sections are connected in parallel across the battery
4. When only one-half of the coil is connected across the battery

Correct answer: When the coil is split into four equal sections and all four sections are connected in parallel across the battery

Solution

Connecting the coil in parallel allows each section to receive the full voltage of the battery, which maximizes the current through each section. Since heat produced in a resistor is proportional to the square of the current (I²R), having more sections in parallel increases the total current and thus the total heat generated.

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