Solder is an alloy of-

Correct option is A

The correct answer is (a) Lead and tin.
· Solder is traditionally an alloy composed primarily of lead and tin. This combination has been widely used for many years due to its low melting point and excellent capability to form durable bonds between metal surfaces.
· The typical formulation for many solders used in electronics and plumbing applications consists of about 60% tin and 40% lead, known as 60/40 solder. This specific ratio provides a good balance between melting point and mechanical strength, making it effective for creating strong, reliable electrical connections and sealing joints.
· However, due to health concerns associated with lead, lead-free solders are increasingly used, especially in consumer electronics and drinking water systems. These are usually composed of various combinations of tin, silver, copper, and other metals.