I don't like the wording of any of the choices on the list.
SONAR generates a short pulse of sound, like a 'peep' or a 'ping',
focused in one direction. If there's a solid object in that direction,
then some of the sound that hits it gets reflected back, toward the
source. The source listens to hear if any of the sound that it sent
out returns to it. If it hears its own 'ping' come back, it measures
the time it took for the sound to go out and come back. That tells
the SONAR equipment that there IS a solid object in that direction,
and also HOW FAR away it is.
RADAR works exactly the same way, except RADAR uses radio waves.
A. Parallel circuit
Short circuits are circuits that is like plugging in a USB into your computer and the other end to your iPhone, so it's not D.
Series circuits can come in all kinds of different shapes, so it's not C.
Open circuits are circuits that are opened, meaning that whenever you turn on the light and it's an open circuit, it won't work cause the two wires are not connected, meaning it's not D.
Parallel circuits are circuits that are in one straight line, just like parallel lines, meaning the answer would be A. (Look at the picture and don't get confused with the other question that's the same question and has the same answers, they both have different pictures, so look at the pictures they give you whenever they ask the question so your getting the right answer)
Hope this helped.
It’s true. longer wavelength means a lower frequency, and a shorter wavelength means a higher frequency!