Electrical Measurements Practice Test 4

1. What is the effect of capacitance on wattmeter reading?

2. Potential transformers are used with _________

3. A (350 A/ 7A), 50 Hz current transformer has a primary bar. The secondary burden is a pure resistance of 1 Ω and it draws a current of 5 A. The magnetic core requires 350 AT for magnetization. Find the percentage ratio error.

4. In A.C. circuits, power consumed is ________

5. What is the effect of frequency on the torque of a moving system?

6. Wattmeters are compensated for errors due to inductance by _________

7. The excitation current of a C.T. _________

8. High magnetizing forces in the core when removed suddenly lead to ____________

9. A moving iron ammeter produces a full-scale torque of 240 μN-m with a deflection of 120° at a current of 10 A. the rate of change of self-inductance (μH/rad) of the instrument at full scale is?

10. V_p is leading in phase, while V_s is lagging in phase.