Theory & DesignCâu 92 / 110
An AC circuit at 240 V draws 12 A. What is the circuit impedance?
a.2 ohms
b.0.05 ohms
c.288 ohms
d.20 ohms
Giải thích
By Ohm's law for AC, Z = V / I = 240 / 12 = 20 ohms.
Luyện miễn phí toàn bộ 110 câu hỏi — không cần đăng ký.
Câu hỏi liên quan cùng chủ đề
- A single-line (one-line) diagram represents an electrical system by:
- A transformer steps 480 V down to 120 V. What is its turns (voltage) ratio?
- A transformer has a 4:1 turns ratio and a 10-A primary current. What is the secondary current (ideal)?
- A continuous load draws 40 A. At what minimum ampacity must the branch-circuit conductors and overcurrent device be rated?
- The demand factor of a system is defined as:
- What are the commonly recommended maximum voltage-drop limits for a branch circuit and for the combined feeder plus branch circuit?
Cập nhật gần nhất: · quy trình kiểm tra
Đội Ngũ Biên Tập PrepPass · Đối chiếu với Master Electrician Licensing Exam (NEC-based) · Quy trình kiểm tra