100 J of heat are produced each second in a 4 `Omega ` resistance. Find the potential difference across the resistor.

Explanation

`H=100 J.R = 4Omega , t = 1 s, V=?`
From Eq. (12.21) we have the current through the resistor as
` I= sqrt((H//Rt))`
`=sqrt([100 J//4 //(4 Omega xx 1 s )])`
`=5A `
thus the potential difference across the ressistor .V [from Eq. ( 12. 5 ) is
`v= IR `
` =5A xx 4Omega `
`= 20 V `