| 1 |
The winding of the electromagnet in motor are usually called. |
- A. Magnetic coils
- B. Field coils
- C. Electric coils
- D. electric o electric coils
|
| 2 |
The jerks in D.C. motor are created by the use of. |
- A. Armature
- B. Commutators
- C. Split rings
- D. Source of emf
|
| 3 |
If 10 A current passes through 100 mH inductor, then energy stored is. |
- A. 100 J
- B. 5 J
- C. 20 J
- D. Zero
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| 4 |
Energy density of an inductor is: |
- A. UM=1/2μ<sub>∘</sub>/B<sup>2</sup>
- B. Um = 2μ<sub>∘</sub>/B
- C. UM = 1/2B<sup>2</sup>/μ<sub>∘</sub>
- D. Um = 2B<sup>2</sup>/μ<sub>∘</sub>
|
| 5 |
In A.C. inductor behaves as |
- A. Capacitor
- B. Resistor
- C. Commutator
- D. Transistor
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| 6 |
EMF is induced due to change in |
- A. Charge
- B. Current
- C. Magnetic flux
- D. Electric field
|
| 7 |
The magnitude of back emf: |
- A. Increases with sped of motor
- B. Decreases with speed of motor
- C. Remains same
- D. None of above
|
| 8 |
B2/2p is the expression of. |
- A. Lenz's law
- B. Magnetic energy
- C. Magnetic energy density
- D. Back emf
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| 9 |
Output of D.C. motor is |
- A. A.C. energy
- B. Mechanical energy
- C. Chemical energy
- D. D.C. energy
|
| 10 |
If the north pole of a magnet moves away from a metallic ring |
- A. Clockwise
- B. Anticlockwise
- C. First clockwise and then anticlockwise
- D. None of above
|