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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. A capacitor of 2,000 pF is greater than
Options- A. 0.02 µF
- B. 0.002 µF
- C. 0.0002 µF
- D. 0.0000002 F Discuss
Correct Answer: 0.0002 µF
- 2. When the turns ratio of a transformer is 20 and the primary ac voltage is 12 V, the secondary voltage is
Options- A. 12 V
- B. 120 V
- C. 240 V
- D. 2,400 V Discuss
Correct Answer: 240 V
- 3. Resistance is measured in
Options- A. henries
- B. ohms
- C. hertz
- D. watts Discuss
Correct Answer: ohms
- 4. What is the flux density in a magnetic field in which the flux in 0.1 m2 is 600 µWb?
Options- A. 6,000 µT
- B. 600 µT
- C. 600 T
- D. 6 T Discuss
Correct Answer: 6,000 µT
- 5. All the voltage drops and the source voltage added together in a series circuit is equal to
Options- A. the total of the voltage drops
- B. the source voltage
- C. zero
- D. the total of the source voltage and the voltage drops Discuss
Correct Answer: zero
- 6. A certain voltage divider consists of three 1 kΩ resistors in series. Which of the following load resistors will have the least effect on the output voltage?
Options- A. 1 MΩ
- B. 100 kΩ
- C. 1 kΩ
- D. 330 Ω Discuss
Correct Answer: 1 MΩ
- 7. A certain series resonant circuit has a bandwidth of 2 kHz. If the existing coil is replaced with one having a higher value of Q, the bandwidth will
Options- A. increase
- B. remain the same
- C. decrease
- D. be less selective Discuss
Correct Answer: decrease
- 8. The first row of a certain determinant has the numbers 3 and 5. The second row has the numbers 7 and 2. The value of this determinant is
Options- A. 31
- B. ?31
- C. 39
- D. ?29 Discuss
Correct Answer: ?29
- 9. An ac circuit consists of a resistor and a capacitor. To increase the phase angle above 45°, the following condition must exist:
Options- A. R = XC
- B. R > XC
- C. R < XC
- D. R = 5XC Discuss
Correct Answer: R < XC
- 10. The stator is the rotating assembly in a generator or motor.
Options- A. True
- B. False Discuss
Correct Answer: False
Explanation:
The two main parts of a generator or motor can be described in either mechanical or electrical terms:
Mechanical:
Rotor: The rotating part of an electrical machine
Stator: The stationary part of an electrical machine
Electrical:
Armature: The power-producing component of an electrical machine. In a generator, alternator, or dynamo the armature windings generate the electric current. The armature can be on either the rotor or the stator.
Field: The magnetic field component of an electrical machine. The magnetic field of the dynamo or alternator can be provided by either electromagnets or permanent magnets mounted on either the rotor or the stator.
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