Here's an electronics riddle:
The assumptions:
1. A heating element that's rated at 3 ohms resistance to input current, 0-1000 watts of consumption power, 0-1000 volts safe input electric potential.
2. This heating element resistance stays constant regardless of temperature.
3. A AA battery is is rated at 1.5v output electric potential and 0-700 mA output current.
The basic operation of the heating element is to use 1 AA battery. That means that the battery outputs 1.5 * (1/3) = 0.5 amps, and the heating element radiates 1.5 * 0.5 = 0.75 watts.
4. Batteries are used to power the heating element, but the batteries are physically far away from the heating element itself (for safety reasons).
5. Each battery in the setup must be within a safe range of current output.
Note that based on the assumptions, the battery output current (0.5 amps) is within the safe range (less than 0.7 amps).
6. The battery's resistance is negligible.
7. The only possible power supply is identical AA batteries.
8. There's only that 1 heating element. No resistors allowed, because resistors are technically a type of heating element.
Here's the question:
How many batteries are required to produce exactly twice the heat (twice the wattage) as the configuration with 1 battery, and in what configuration to set up the batteries?