Theory & SafetyCâu 112 / 120
On a 208Y/120-volt wye system, what is the relationship between line voltage and phase voltage?
a.Line voltage equals phase voltage divided by 1.732
b.Line voltage equals phase voltage
c.Line voltage equals phase voltage multiplied by 3
d.Line voltage equals phase voltage multiplied by 1.732
Giải thích
In a wye configuration the line voltage is the square root of three times the phase voltage: 120 x 1.732 = 208 volts, while line current equals phase current. In a delta configuration the relationship reverses, with line voltage equal to phase voltage and line current equal to 1.732 times phase current.
Luyện miễn phí toàn bộ 120 câu hỏi — không cần đăng ký.
Câu hỏi liên quan cùng chủ đề
- Three resistors of 10, 15 and 25 ohms are connected in series across 120 volts. What is the circuit current?
- A 20-ohm resistor and a 30-ohm resistor are connected in parallel. What is the total resistance?
- A balanced three-phase load draws 40 amperes at 480 volts with a power factor of 0.85. What is the true power?
- A balanced delta-connected load has a phase current of 20 amperes. What is the line current?
- A single-phase transformer has a 480-volt primary and a 120-volt secondary. If the secondary carries 100 amperes, what is the approximate primary current?
- What is the secondary full-load current of a 25 kVA single-phase transformer with a 240-volt secondary?
Cập nhật gần nhất: · quy trình kiểm tra
Đội Ngũ Biên Tập PrepPass · Đối chiếu với Journeyman Electrician Licensing Exam (NEC-based) · Quy trình kiểm tra