So you would divide 1530 by 8 and that’s how you’d get your answer, so it should be (blank)m
B) It’s material moves due to convection currents.
Answer:
The ratio of the diameter of iron to Cu is;

Explanation:
R=(ρL)/A
- R is resistance,
- L is length,
- A is area,
- ρ is resistivity
- d is diameter
from the question the two materials have the same resistance per unit length.

for iron =
for copper
This means we can equate ρ/A for both materials.

re-arranging the equation we have,





C: if it senses unequal currents