If power dissipated in the `9 Omega` resistor in the resistor shown is `36 W`, the potential difference across the `2 Omega` resistor is

Options

A. `8 V`
B. `10 V`
C. `2 V`
D. `4 V`

Answer

B

Explanation

(b) Electric power, `p = i^(2) R`
`:.` Current, `I = sqrt((p)/(R ))`
Fro resistance of `9 Omega`
`i_(1) = sqrt((36)/(9)) = sqrt4 = 2 A`
`i_(2) = (i_(1) xx R)/(6) = (2 xx 9)/(6) = 3 A`
`i- i_(1) + i_(2) = 2 + 3 = 5A`
`V_(2) = IR_(2) = 5 xx 2 = 10 V`