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The correct answer is option 1: Nickel and cadmium. These two materials are used as electrodes in rechargeable batteries, more specifically known as Ni-Cd (Nickel Cadmium) batteries. These are widely used in portable devices like torchlights and electric shavers due to their ability to produce a constant output voltage throughout their discharge cycle.
Option 2: Zinc and carbon - these are often used in non-rechargeable, or primary batteries such as zinc-carbon or zinc-chloride batteries, cannot be recharged once drained.
Option 3: Lead peroxide and lead - these are the electrodes of a lead-acid battery, usually used in cars, UPS systems, and other heavy-duty applications. These batteries are rechargeable but are less common in small devices.
Option 4: Iron and cadmium - This is not a common pairing for batteries. Cadmium is usually paired with Nickel (as in option 1) in rechargeable batteries, while iron isn`t typically used as a electrode in batteries.