Zzzzzz what is the current through the circuit a 2 1

37. Zzzzzz... What is the current through the circuit?
A. 2 . 1 A B. 0 . 92 A C. 0 . 73 A D. 0 . 057 A
Solution: Calculate for the impedance.
Z =
p
R 2 + ( X
L
- X
C
) 2 =
p
(1 . 6 Omega) 2 + (3 . 8 Omega - 5 . 4 Omega) 2 = 2 . 3 Ω
Use Ohm’s law to solve for the current.
V = IZ -→ I =
V
Z
=
5 . 0 V
2 . 3 Ω
= 2 . 1 A .
38. Phase the truth. Which of the following is TRUE?
39. Maikuro renji. A microwave oven from Japan is designed to run at 110 V AC. It is then
required to run on 220 V AC here in the Philippines, using a transformer. If the oven is
to be connected to the secondary winding, which of the following transformer designs is
appropriate in this situation?

Second Long Exam Midyear, AY 2015–2016 Physics 72
40. Dingdong. A doorbell requires 0 . 40 A of alternating current. An ideal transformer has
2000 turns in the primary and 100 turns in the secondary. What is the current in the pri-
mary?

Second Long Exam Midyear, AY 2015–2016 Physics 72