Discussion
Home ‣ Electrical Engineering ‣ Energy and Power See What Others Are Saying!
- Question
A power supply produces a 0.6 W output with an input of 0.7 W. Its percentage of efficiency is
Options- A. 8.57%
- B. 42.85%
- C. 4.28%
- D. 85.7%
- Correct Answer
- 85.7%
- 1. You are measuring the current in a circuit that is operated on an 18 V battery. The ammeter reads 40 mA. Later you notice the current has dropped to 20 mA. How much has the voltage changed?
Options- A. 9 V
- B. 900 mV
- C. 0 V
- D. 18 V Discuss
- 2. A certain amplifier has 600 Ω internal resistance looking from its output. In order to provide maximum power to a 4 Ω speaker, what turns ratio must be used in the coupling transformer?
Options- A. 8
- B. 0.8
- C. 0.08
- D. 80 Discuss
- 3. In a Y-connected generator, there is a 120° difference between each line voltage and the nearest phase voltage.
Options- A. True
- B. False Discuss
- 4. When the frequency of the voltage applied to a series RC circuit is decreased, the impedance
Options- A. increases
- B. decreases
- C. remains the same
- D. doubles Discuss
- 5. The maximum output voltage of a certain low-pass filter is 15 V. The output voltage at the critical frequency is
Options- A. 0 V
- B. 15 V
- C. 10.60 V
- D. 21.21 V Discuss
- 6. Find I2. 4I1 + 4I2 = 2
6I1 + 7I2 = 4
Options- A. 1 A
- B. ?1 A
- C. 100 mA
- D. ?100 mA Discuss
- 7. One sine wave has a positive-going zero crossing at 15° and another sine wave has a positive-going zero crossing at 55°. The phase angle between the two waveforms is
Options- A. 0°
- B. 45°
- C. 40°
- D. none of the above Discuss
- 8. The number 65,000 expressed in scientific notation as a number between 1 and 10 times a power of ten is
Options- A. 0.65 × 104
- B. 6.5 × 104
- C. 65 × 104
- D. 650 × 103 Discuss
- 9. In applying the superposition theorem,
Options- A. the sources are considered one at a time with all others replaced by their internal impedance
- B. all sources are considered independently
- C. all sources are considered simultaneously
- D. the sources are considered one at a time with all others replaced by their internal resistance Discuss
- 10. The roll-off rate of a basic RC or RL filter is 20 dB per decade.
Options- A. True
- B. False Discuss
More questions
Correct Answer: 9 V
Correct Answer: 0.08
Correct Answer: False
Correct Answer: increases
Correct Answer: 10.60 V
Correct Answer: 1 A
Correct Answer: 40°
Correct Answer: 6.5 × 104
Correct Answer: the sources are considered one at a time with all others replaced by their internal impedance
Correct Answer: True
Comments
There are no comments.More in Electrical Engineering:
Programming
Copyright ©CuriousTab. All rights reserved.