Is the cornet and tuba in same family?

Yes, the cornet and tuba are both members of the brass family of instruments. Brass instruments are characterized by their use of a mouthpiece to produce sound, which is then amplified by a resonating chamber or bell. The cornet is a high-pitched, valved brass instrument that is similar to a trumpet, while the tuba is a low-pitched, valved brass instrument that is the largest member of the family. Both instruments are used in a variety of musical settings, from classical orchestras to jazz bands.