MCQOPTIONS
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MCQOPTIONS
This section includes 9 Mcqs, each offering curated multiple-choice questions to sharpen your Electrical Measurements knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
The CT supplies current to the current coil of a wattmeter power factor meter, energy meter and, an ammeter. These are connected as? |
| A. | All coils in parallel |
| B. | All coils in series |
| C. | Series-parallel connection with two in each arm |
| D. | Series-parallel connection with one in each arm |
| Answer» C. Series-parallel connection with two in each arm | |
| 2. |
Usually a CT has ____________ |
| A. | Power overload capacity than PT |
| B. | The same overload capacity as a PT |
| C. | A higher overload capacity than a PT |
| D. | No overload capacity |
| Answer» D. No overload capacity | |
| 3. |
The observation when the secondary winding of a current transformer is open-circuited is? |
| A. | The whole of the primary current produces a large value of flux in the core thereby producing a large voltage in the secondary winding |
| B. | The large voltage may act as a safety hazard for the operators and many even raptures the insulation |
| C. | When the large magnetizing force is taken off, it leaves a large value of residual magnetism |
| D. | When the large magnetizing force is taken off, it leaves a small value of residual magnetism |
| Answer» C. When the large magnetizing force is taken off, it leaves a large value of residual magnetism | |
| 4. |
A (350 A/ 7A), 50 Hz current transformer has a primary bar. The secondary burden is a pure resistance of 1 and it draws a current of 5 A. The magnetic core requires 350 AT for magnetization. Find the percentage ratio error. |
| A. | 10.56 |
| B. | -28.57 |
| C. | 11.80 |
| D. | -11.80 |
| Answer» C. 11.80 | |
| 5. |
A 200/1 Current Transformer (CT) is wound with 400 turns on the secondary on a toroidal core. When it carries a current of 180 A on the primary, the ratio is found to be -0.5%. If the number of secondary turns is reduced by 1, the new ratio error (in %) will be? |
| A. | 0.0 |
| B. | -0.5 |
| C. | -1.0 |
| D. | -2.0 |
| Answer» D. -2.0 | |
| 6. |
A 1000/5 A, 50 Hz correct transformer has a secondary burden comprising a non-inductance of 2 . What is the ratio error, if the iron loss is 3 W and magnetizing mmf is 250 A? |
| A. | 4% |
| B. | 5.7% |
| C. | 3.6% |
| D. | 4.8% |
| Answer» C. 3.6% | |
| 7. |
A 1000/5 A, 50 Hz correct transformer has a secondary burden comprising a non-inductance of 1.6 . The flux in the core at full load is? |
| A. | 160 Wb |
| B. | 180 Wb |
| C. | 200 Wb |
| D. | 150 Wb |
| Answer» C. 200 Wb | |
| 8. |
A 50 Hz, bar primary CT has a secondary with 500 turns. The secondary supplies 5 A current into a purely resistive burden of 1 . The magnetizing ampere-turns are 200. What is the ratio error at full load, if the iron loss is 1.5 W and magnetizing mmf is 100 A? |
| A. | Zero |
| B. | 45 Wb |
| C. | 25.5 Wb |
| D. | 100 Wb |
| Answer» C. 25.5 Wb | |
| 9. |
A 50 Hz, bar primary CT has a secondary with 800 turns. The secondary supplies 7 A current into a purely resistive burden of 2 . The magnetizing ampere-turns are 300. The phase angle is? |
| A. | 3.1 |
| B. | 85.4 |
| C. | 94.6 |
| D. | 175.4 |
| Answer» B. 85.4 | |