Physics

Problem

Three wires P, Q, and R are made of the same metal. • Wire P has length

l

and diameter

d

. • Wire Q has length

2l

and diameter

d

. • Wire R has length

l

and diameter

\tfrac{d}{2}

. Rank the wires by resistance from smallest to largest. a)

R<P<Q

P<Q<R

Q<P<R

P<R<Q