| 1 |
The application of mutual induction is a. |
- A. D.C. motor
- B. Radio
- C. Television
- D. Transformer
|
| 2 |
Output of D.C. motor is |
- A. A.C. energy
- B. Mechanical energy
- C. Chemical energy
- D. D.C. energy
|
| 3 |
In A.C. generator , when plane of coil is perpendicular to magnetic field, then output of generator is. |
- A. NwAB
- B. 2pi f
- C. Maximum
- D. Zero
|
| 4 |
Unit of self inductance is |
- A. Weber
- B. Tesla
- C. Henry
- D. Farad
|
| 5 |
If magnetic field is doubled then magnetic energy density becomes. |
- A. Four times
- B. Two times
- C. Three times
- D. Six times
|
| 6 |
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
|
| 7 |
If a step up transformer were 100% efficient the primary and secondary winging's would have the same. |
- A. Current
- B. Power
- C. Voltage
- D. Direction of winding
|
| 8 |
Energy density in an inductor is. |
- A. Directly proportional to magnetic field
- B. Directly proportional to square of magnetic field
- C. Inversely proportional to magnetic field
- D. Inversely proportional to square of magnetic field
|
| 9 |
When the back emf in a current is zero, it draws |
- A. Zero current
- B. Maximum current
- C. Minimum current
- D. Steady average current
|
| 10 |
A real transformer does not change. |
- A. Voltage level
- B. Current level
- C. Power level
- D. Frequency
|