Which instrument is slightly larger and lower in pitch than the violin, and belongs to the string family?

The instrument that is slightly larger and lower in pitch than the violin, belonging to the string family, is the viola. The viola is specifically designed to complement the violin, offering a richer, deeper sound due to its larger body and thicker strings. This results in a lower pitch range compared to the violin, which is higher and brighter in tone. The viola typically sounds a fifth lower than the violin, making it an essential part of string quartets and orchestras, enriching the overall string harmony.

In contrast, the cello is even larger and has a significantly lower pitch, while the double bass is the largest of the string instruments, producing the lowest pitches in the string family. The harp, while also part of the broader string family, is a plucked instrument and does not share the same characteristics in terms of size and pitch relative to the violin as the viola does.