Which one of the following pairs of materials serves as electrodes in chargeable batteries commonly used in devices such as torchlights, electric shavers, etc?

1. Chargeable batteries, also known as secondary batteries or rechargeable batteries, use reversible chemical reactions to store energy. 2. The question asks about materials serving as electrodes in chargeable batteries commonly used in devices like torchlights and electric shavers. 3. Nickel-cadmium (NiCd) batteries were widely used in such portable devices during the era this question was asked (1995). In a NiCd battery, the positive electrode is typically nickel hydroxide and the negative electrode is cadmium. 4. Zinc and carbon are used in primary (non-rechargeable) zinc-carbon batteries. 5. Lead peroxide and lead are used in lead-acid batteries, common in cars but less so in small devices like torchlights. 6. Iron is not typically paired with cadmium in common rechargeable batteries for these applications.