How electromagnetism works

Electric currents are created when electrons move from atom to atom within a solid metal wire. We measure currents in amperes (A). An electromagnetic field is created by connecting a piece of wire to both ends of a battery and wrapping the wire around a nail at the center. Turning on the electrical current produces a magnetic field.

they should be similar or the same

when a device is used in a circuit in which the voltage is 81 v, the current flowing through the device is 3 a. what is the resistance of the device?

a. 27 ω

b. 40.5 a

c. 243 ω

d. 243 a

the correct answer is a. 27