RC Circuits - Technical MCQs

Q1:

What is the voltage drop across R1 in the given circuit?

A 10 V

B 4.80 V

C 4.00 V

D 5.80 V

ANS:D - 5.80 V

1. Get the inverse (1/333 - 1/250i)^-1 to get the impedance since it is in admittance form, then it will be equal to 120.03 + 159.88i.
2. Then next step is to add that to (180 - 240i).
3. And, (120.03 + 159.88i) + (180 - 240i) = 300.09 - 80.12i.
4. Then convert that to Polar form which is equal to 310.55 <-14.95.
5. Now the total impedance is 310.55, and by voltage divider formula Vr1 = (10/310.55)(180) = 5.8 volts.