Final answer:
Yes, the speed of electricity can vary in different materials, similar to the speed of light. The Michelson-Morley experiment was conducted to prove this.
Step-by-step explanation:
Yes, the speed of electricity can vary in different materials, similar to the speed of light. The experiment that was conducted to prove this is called the Michelson-Morley experiment. In the mid-1880s, American physicists A. A. Michelson and E. W. Morley made direct measurements of the speed of light. Their results showed that the speed of light is the same in all directions, regardless of the Earth's motion around the Sun. This experiment confirmed that the speed of light, and by extension, the speed of electricity, is independent of the medium it travels through.