An electric current is created in a long thin wire. how will increasing the current and changing the direction of the current effect the direction that a compass placed under the wire will point?
a)
it compass will spin continuously.
b)
the compass will flip exactly 180 degrees.
c)
the compass will spin exactly 360 degrees.
d)
the compass will not react and still point north.

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.