The electricity generated in a closed loop of copper coil or any other material is primarily determined by the rate of change of the magnetic field passing through the loop. This phenomenon is known as electromagnetic induction.
When a magnet is moved through the coil, the magnetic field lines passing through the coil change, inducing an electric current in the coil. The magnitude of the induced current depends on several factors:
Speed: The faster the magnet moves through the coil, the greater the rate of change of the magnetic field, resulting in a stronger induced current. Therefore, increasing the speed of the magnet will increase the amount of electricity generated.
Magnetic field strength: The strength of the magnetic field produced by the magnet also affects the amount of electricity generated. A stronger magnet will induce a larger current in the coil compared to a weaker magnet, assuming the speed remains constant.
Coil properties: The properties of the copper coil, such as the number of turns, the area of the loop, and the resistance of the wire, also influence the amount of electricity generated. A coil with more turns and a larger area will generally induce a larger current.
So, in answer to your question, the electricity generated would be influenced by both the speed of the magnet and the size (strength) of the magnet. Increasing either the speed or the strength of the magnet, within certain practical limits, would result in an increase in the electricity generated.