A metal resistance wire with length $l$ and cross-sectional area $A$ has resistance $R$. For a metal wire made from the same material, with length $2l$ and cross-sectional area $\frac{A}{2}$, what is its resistance?
- A$\frac{R}{4}$
- B$R$
- C$2R$
- D$4R$
Physics 0625 · IGCSE · Electrical quantities