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

Nickel and cadmium are the primary materials used in Nickel Cadmium or NiCd batteries, which are a common type of rechargeable battery. In these batteries, nickel oxide hydroxide serves as the positive electrode and metallic cadmium serves as the negative electrode. These batteries are widely used in portable devices like torchlights and electric shavers because they can be recharged hundreds of times and maintain a steady voltage. Option B refers to non rechargeable dry cells, while option C refers to lead acid batteries typically found in vehicles. Option D is not a standard combination for common consumer electronics. Therefore, option A is the correct answer.