The tuba, by far. It's a much larger instrument.
Horn, Trumpet, Trombone, and tuba.
trumpet, trombone, baritone, tuba, and french horn
Tuba is from the Latin for horn or trumpet.
Trumpet, by two octaves
A trumpet has a higher tone than a tuba because it has less length of tubing.
Assuming you mean "tuba" and assuming you mean "why does the tuba play lower notes than the trumpet," the basic answer is, because the tuba is longer (it has more tubing).
The trumpet, trombone and tuba are brass instruments. They begin with the letter t.
Trumpet,French Horn ,Trumbone andTuba
Larger (longer and wider) pipes have a lower resonant frequency than smaller ones. The typical "trumpet" (which is often actually a cornet) plays about two octaves higher than a typical tuba.
The word tuba is from the Latin word tuba meaning a "straight bronze war trumpet."
Trumpet, trombone, and tuba are all brass instruments. The other is a percussion instrument.
The knobs on the tuba and Trumpet are called valves. The knobs on a french horn are often called valves or rotors. You use valve oil on the tuba and trumpet, while you use rotor oil for the french horn.