Two wires that are made up of two different materials whose specific resistance are in the ratio 2 : 3, length 3 : 4 and area 4 : 5. The ratio of their resistances is

Options

A. `6:5`
B. `6:8`
C. `5:8`
D. `1:2`

Answer

C

Explanation

Resistance, `R=rho(l)/(A)`
`therefore (R_(1))/(R_(2))=(rho_(1))/(rho_(2))xx(l_(1))/(l_(2))xx(A_(2))/(A_(1))=(2)/(3)xx(3)/(4)xx(5)/(4)=(5)/(8)`