Two wires of the same material and equal length are joined in parallel combination. If one of them has half the thickness of the other and the thinner wire has a resistance of 8 ohms , the resistance of the combination is equal to

Options

A. `5/8` ohm
B. `8/5` ohm
C. `3/8` ohm
D. `8/3` ohm

Answer

B

Explanation

`I_(1) = I_(2) = I, rho_(1) = rho_(2)= rho, A_(1) = A, A_(2) = 2A`
`R_(1)/R_(2) =(4A)/A rArr R_(1) = 4R_(2)`
`R_(1) = 8 Omega, R_(2) = 2Omega`
`R_(eq) = (8 xx 2)/10 = 8/5 Omega`