What are the constituents of alloy solder ?

What are the constituents of alloy solder ?

Pb and Zn
Pb and Sn
Pb and Si
Pb and Co
This question was previously asked in
UPSC CDS-2 – 2021
Solder is a fusible metal alloy used for joining materials by melting the solder and causing it to flow into the joint. The most common type of solder used in electronics and plumbing is a eutectic alloy of tin (Sn) and lead (Pb). While lead-free solders using tin alloys with silver or copper are now common due to environmental concerns regarding lead, traditional and historically significant solders are alloys of lead and tin. Among the given options, Pb and Sn are the constituents of common solder.
– Solder is a metal alloy used for joining metals.
– Common solder alloys primarily consist of tin and lead.
The melting point of solder is lower than that of the metals being joined, allowing it to melt and bond without melting the base metals. The ratio of tin to lead affects the melting point and properties of the solder. Eutectic solder (63% Sn, 37% Pb) has a single melting point, whereas non-eutectic solders melt over a range of temperatures.