18)
an electromagnet is created using a battery, an insulated copper wire and an iron nail. the wire is wra
times and attached to the battery. which pair of changes will definitely increase the strength of the electr
increase the voltage of the battery and decrease the number of turns of the
coil.
decrease the voltage of the battery and decrease the number of turns of
the coil.
increase the voltage of the battery and increase the number of turns of the
coil.
decrease the voltage of the battery and increase the number of turns of
the coil.
19)
describe how resistance affects the flow of current in a circuit.
Differences in the density of water can also cause currents to form and move. Density is affected by temperature and salinity. Cold water or water with dissolvedsalts (higher salinity) is denser than warm water or water without dissolved salts.
d
Explanation:
The answer is D) The FLOW of current in a circuit is reduced by resistance from collisions of the electrons within the wire.. because When starting I think it's useful to think of electron current flowing through wires like water current flowing through pipes.