An electric iron of resistance `20 Omega` takes a current of `5 A`. Calculate the heat developed in `30 s`.

Explanation

Here, Current, `I = 5A`
Resistance, `R = 20 Omega`
And, Time, `t = 30s`
Now, Heat produced, `H = I6(2) xx R xx t`
`H = (5)^(2) xx 20 xx 30`
`H = 25 xx 20 xx 30`
`H = 15000 J`
Thus, the heat developed is 15000 joules.