## Question:

For the circuit in the Figure , assume that ${ V }_{ BO }$ for the DIAC is 30 V, ${ C }_{ 1 }$ is 1 $\mu$F, R is adjustable in the range 1-20 k $\Omega$, and that switch S1 is open. What is the firing angle of the circuit when R is 10 k $\Omega$? What is the rms voltage on the load under these conditions?