A change that would most improve his results would be; D) Connecting the galvanometer to the coil
But friction is what would make it slow down so...
Answer:
Hope this help you!!
Explanation:
Crust : The crust is the thinnest layer of the Earth. It has an average thickness of about 18 miles below land, and around 6 miles below the oceans. The crust is the layer that makes up the Earth's surface and it lies on top of a harder layer, called the mantle.
Mantle : The mantle is the mostly-solid bulk of Earth's interior. The mantle lies between Earth's dense, super-heated core and its thin outer layer, the crust. The mantle is about 1,802 miles thick, and makes up a whopping 84% of Earth's total volume
Outer Core : The outer core is the third layer of the Earth. It is the only liquid layer, and is mainly made up of the metals iron and nickel, as well as small amounts of other substances. The outer core is responsible for Earth's magnetic field. As Earth spins on its axis, the iron inside the liquid outer core moves around.
Inner Core : It's Almost The Size of the Moon. The Earth's inner core is surprisingly large, measuring 1,516 miles across. It's Mostly Made of Iron. It Spins Faster Than the Surface of the Earth. It Creates a Magnetic Field.
