A student builds an electromagnet using a battery, a plastic nail, and some thin insulated wire. The wire is wrapped around the nail 10 times and then connected to the battery. What changes could the student make to increase the strength of the electromagnet? Select ALL that apply.

A.
increase the length of the wire

B.
decrease the voltage of the battery

C.
place a small magnet near the battery

D.
replace the plastic nail with an iron nail

E.
wrap more loops of wire around the nail

F.
replace the wire with a wire that has less resistance

Two loudspeakers, 5.5 m apart and facing each other, play identical sounds of the same frequency. you stand halfway between them, where there is a maximum of sound intensity. moving from this point toward one of the speakers, you encounter a minimum of sound intensity when you have moved 0.33 m . assume the speed of sound is 340 m/s. part a) what is the frequency of the sound? part b) if the frequency is then increased while you remain 0.21 m from the center, what is the first frequency for which that location will be a maximum of sound intensity? express your answer to two significant figures and include the appropriate units.