Answer:
C
Explanation:
To generate an electric current in one of the copper wire coils, Theresa can utilize the principle of electromagnetic induction. This principle states that a changing magnetic field can induce an electromotive force (EMF) in a conductor, such as copper wire. Among the options provided, the correct method for inducing a current is **C. Move the magnet up and down near one of the coils**.
When Theresa moves the magnet, the magnetic field around the coil changes, leading to a variation in magnetic flux through the coil. This change in flux induces an electric current in the wire, provided that the circuit is closed. The motion of the magnet creates a dynamic interaction with the magnetic field, which is essential for generating electricity through induction.
In contrast, the other options would not successfully induce a current. For instance, **A. Remove a length of wire from one of the coils** would simply alter the coil's structure without causing any electromagnetic induction. **B. Carefully touch the magnet to one of the coils** might create a magnetic field, but it does not result in a change in magnetic flux, which is necessary for inducing a current. Lastly, **D. Disconnect the coils and place them side by side** does not involve any movement or change in the magnetic field, thus failing to generate an electric current.
In summary, by moving the magnet up and down near the coil, Theresa effectively harnesses the principles of electromagnetic induction to create an electric current in the copper wire.