18. what happens if you cut a bar magnet in half?
a. you get two north pole magnets
b. you get a north pole magnet and a south pole magnet
c. you get two south pole magnets
d. you get two smaller magnets, each with a north and south pole

My best guess would be b) You get a North pole magnet and a South pole magnet

hope this helps!

sonar - device which is used to find the submit submarines, sankalp ship. sonar waves consists of a transmitter and detector which are installed in the observation centre on board of a ship. the ultrasonic waves are sent into the sea at high frequency about 1000 khz in all direction.

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.