Question

how does oil birds use ultrasound

Answer 1

OIl birds use ultrasound to navigate their way and get to know the direction as they do not have the normal sight, so these wave when hit the surface and come back to their ears they get to know what is in front of them and which way to go 

Answer 2

Explanation:

Voltmeters have high resistance. When it is connected in series it decreases the current going to the circuit. While Ammeters are very low in resistance. SO when connected in parallel the current wouldbypass the circuit, all go through the ammeter, and blow out theammeter.