What creates the magnetic field in an electromagnet?

a electric current through a straight piece of metal

b magnetic fields around a straight wire

c electric current through a wire coil

d all of these

Aneuron is stimulated with an electric pulse. the action potential is detected at a point 3.70 cm down the axon 0.0052 s later. when the action potential is detected 7.20 cm from the point of stimulation, the time required is 0.0063 s. what is the speed of the electric pulse along the axon? (why are two measurements needed instead of only one? )

The bacteria inside a tube worm would be analogous to what organism in the ocean ecosystem near the waters surface? a. photosynthetic algae b. shrimp c. clown fish d. parasitic lamprey

The dense layer of connective tissue that surrounds an entire skeletal muscle is the