Question

Two cylindrical resistors are made from copper. The first one is of length L and of radius r . The 2nd resistor is of length 6L and of radius 2r. The ratio of these two resistances R1/R2 is:

Answer 1

`R1/R2=(2)/(3)`

Step-by-step explanation:

From the question we are told that:

1st's Length
`l=L`

1st's radius
`r=r`

2nd's Length
`l=6L`

2nd's radius
`r=2r`

Generally the equation for Resistance R is mathematically given by

`R=(\rho L)/(\pi r^2)`

Therefore

`R_1=(\rho L)/(\pi r^2)`

And

`R_2=(\rho 6L)/(\pi (2r)^2)`

Therefore

`R1/R2=((\rho L)/(\pi r^2))/((\rho 6L)/(\pi (2r)^2))`

`R1/R2=(2)/(3)`