True/false: if an object stays still, but the observer moves, the doppler effect is still observered

The statement," If an object stays still, but the observer moves, the Doppler Effect is still observed" is true and satisfy the condition of Doppler Effect.

A system of source of sound waves and observer, such that there is variation in the frequency of sound due to the motion of either source or the observer. Then such variation of frequency is determined using the Doppler Effect.

In general, Doppler effect is defined as the apparent difference between the frequency of source of sound moving relative to the observer or vice versa. So, the application of Doppler's effect is easily noticed with a moving source and stationary observer. Hence, the Doppler's effect is still observed  if an object stays still, but the observer moves.

So, the statement is true.

Thus, we can conclude that the statement," If an object stays still, but the observer moves, the Doppler Effect is still observed" is true and satisfy the condition of Doppler Effect.

Learn more about the Doppler Effect here:

link

there is no correct list among the choices you've provided.

the list might look something like this:

-- baby human

-- piccolo

-- flute

-- soprano singer

-- trumpet

-- tenor singer

-- trombone

-- baritone singer

-- baritone horn

-- bass singer

-- tuba

since i had to make up the list myself, i made it easy on myself, and i didn't try to shuffle the string instruments and woodwinds into it too.