Question

An AC voltage source, with a peak output of 120 V, results in dissipation of energy in a resistor at rate of 100 W. What is the value of the resistance?

Answer 1

`72 Omega`

Explanation:

The relationship is given as,

`P=V^2/R` ,where, `P` is the power dissipated across a resistor of resistance `R` due to R.M.S voltage `V`

Now,we know that, R.M.S voltage = Peak voltage /`sqrt(2)`

Given, peak voltage =`120V`

so, R.M.S voltage wil be =`120/sqrt(2) V`

And also given, `P=100W`

So,putting the values we get,

`R=V^2/P =(120^2/2)/100=72Omega`