| 1 |
When a conductor moves across a magnetic field an emf is set up this emf is called. |
- A. Variable emf
- B. Constant emf
- C. Back emf
- D. Induced emf
|
| 2 |
Energy stored in inductor is. |
- A. 1/2 L I<sup>2</sup>
- B. 1/2 LI
- C. 1/2 L2I
- D. 1/2 L2I2
|
| 3 |
If D.C. input for step up transformer, the output is |
- A. Zero
- B. High
- C. Low
- D. May be high or low
|
| 4 |
|
- A. Lenz's law
- B. Faraday's law
- C. Ampere's law
- D. None of these
|
| 5 |
The north pole of a magnet is brought near a metallic ring. The direction of induced current in the ring will be: |
- A. Antoclockwise
- B. Clockwise
- C. First Clockwise and then Antoclockwise
- D. First anticlockwise and then Clockwise
|
| 6 |
When motor is just started, back emf is almost. |
- A. Maximum
- B. Zero
- C. Minimum
- D. Infinite
|
| 7 |
Commentator was invented by |
- A. Henry
- B. Ousted
- C. Maxwell
- D. William sturgeon
|
| 8 |
Mutual induction has a practical role in the performance of the. |
- A. Radio choke
- B. Transformers
- C. A.C. Generator
- D. D.C. Generator
|
| 9 |
Lenz's law was given by Heinrich lenz in: |
- A. 1894
- B. 1904
- C. 1854
- D. 1834
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| 10 |
The induced emf in a coil is proportional to: |
- A. Magnetic flux through the coil
- B. Rate of change of Magnetic flux through the coil
- C. Area of the coil
- D. Product of magnetic flux flux and area of the coil
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