What type of electric cell would be best in a flashlight or smoke detector? Explain each choice

Flashlight or smoke detector have simple dry cell or batteries.

The cell are generally of 6 volts.

In these cells Zn acts as anode and graphite electrode acts as cathode.

A mixture of MnO2 and carbon blacks surrounds the graphite cathode

The electrolyte is ZnCl2 and ammonium chloride. This mixture is used as thick paste.

Answer:The best electric cells for a flashlight is the rechargeable alkaline battery and the 9v rechargeable lithium batteries in smoke detector.