4. When an ice cube in a glass of water melts, does the water level in the glass rise or fall or remain unchanged? Explain your answer. What law guides
your answer?

it remains unchanged

Explanation:

it remains unchanged because the ice was already in there unless it was taken out then the water would have gone down.

r=rho l/a where a is the area, l is the length and rho is resistivity so the greater the area the lesser the resistance thats why the earth pin is thicker bcos current follow the shortest path, so less resistive .