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- Question
A step-down transformer has a turns ratio less than 1.
Options- A. True
- B. False
- Correct Answer
- True
ExplanationNs/Np is known as the turns ratio.
In step down transformer the number of turns in secondary winding (Ns) will be less than the number of turns in primary (Np).
Therefore, the ratio will be less than 1 for step down transformer.
Ex: Np = 10, Ns = 5; Turns ratio = 5/10 = 0.5.
More questions
- 1. The induced voltage across a coil with 250 turns that is located in a magnetic field that is changing at a rate of 8 Wb/s is
Options- A. 1,000 V
- B. 2,000 V
- C. 31.25 V
- D. 3,125 V Discuss
Correct Answer: 2,000 V
- 2. A 10 Ω resistor, a 90 mH coil, and a 0.015 µF capacitor are in series across an ac source. The impedance magnitude at 1,200 Hz below fr is
Options- A. 1,616 Ω
- B. 161 Ω
- C. 3,387 Ω
- D. 1,771 Ω Discuss
Correct Answer: 1,616 Ω
- 3. Approximately how much current flows through a 3.3 MΩ resistor across a 30 V source?
Options- A. 9 µA
- B. 90 µA
- C. 900 µA
- D. 9000 µA Discuss
Correct Answer: 9 µA
- 4. In a certain transformer, the input power to the primary is 120 W. If 8.5 W are lost to the winding resistance, what is the output power to the load, neglecting any other issues?
Options- A. 0 W
- B. 14.1 W
- C. 111.5 W
- D. 1,020 W Discuss
Correct Answer: 111.5 W
- 5. A balanced load is one in which all the impedances are equal.
Options- A. True
- B. False Discuss
Correct Answer: True
- 6. A 470 Ω resistor, a 220 Ω resistor, and a 100 Ω resistor are all in parallel. The total resistance is approximately
Options- A. 790 Ω
- B. 470 Ω
- C. 60 Ω
- D. 30 Ω Discuss
Correct Answer: 60 Ω
Explanation:
1/R = (1/470 + 1/220 + 1/100)
R = 59.98 ohm- 7. What kVA rating is required for a transformer that must handle a maximum load current of 8 A with a secondary voltage of 2 kV?
Options- A. 4 kVA
- B. 0.25 kVA
- C. 16 kVA
- D. 8 kVA Discuss
Correct Answer: 16 kVA
- 8. In a series RLC circuit, the current is minimum at resonance.
Options- A. True
- B. False Discuss
Correct Answer: False
- 9. In a series circuit, the individual powers are additive.
Options- A. True
- B. False Discuss
Correct Answer: True
- 10. If the voltage is stepped up, the current is stepped down, and vice versa.
Options- A. True
- B. False Discuss
Correct Answer: True
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