Question

10. With the aid of illustrations show how current transformers are connected in Delta and wye to measure transmission line currents. Clearly show the polarity sides of the CTs and relay terminals, and the currents flowing in the various branches of the circuit.

11. What is the difference between a transducer and a sensor?

12. How can temperature, displacement, pressure and flow transducers be useful to engineers?

13. Explain the operation principle of a piezoelectric transducer and its main application in day to day life.

14. Briefly explain the operation principle of the Venture tube used to measure the flow of fluids like water and oil in pipe.

15. Make a sketch of a circuit representing a LVDT and explain its operation principles.

16. With the aid of an illustration, clearly explain the operation principles of the CRO.

17. Make sketches of circuit diagrams showing how single, double and triple wattmeter methods can be used in the measurements of three phase power. Write down the expression for determining of the sum of readings from the all the wattmeters involved in each scenarios.

18. With the aid of an illustration, clearly explain the operation principles of a CRO and its main applications.

19. Two wattmeters are used to measure power consumption in 3 phase system indicate: W1=2000 W and W2=500W. Determine the power factor (a) if both readings are positive and, (b) if the reading of W2 is negative.

20. In a balanced 3 phase circuit, power is measured by two wattmeters. If the ratio of the two wattmeter readings is 3:1, determine the power factor of the system.

21. A 3 phase 15 kVA load has a PF of 0.34. The power was measured by two wattmeter method. Find the reading of each wattmeter (i) when the PF is leading, (ii) when PF is lagging.

22. Derive the formula for determining (a) the PF of a 3 phase delta connected and leading load, (b) the PF of 3 phase star connected and leading load.

23. What are the main applications of instruments transformers?

24. With the help of a block diagram , explain the operation of a digital multi-meter

25. Compare the advantages and disadvantages of digital instruments

26. State the advantages TVM over VTVM.

27. Compare the Advantages and disadvantages of reed type frequency meters

28. Explain the operation of principles of the reed type frequency meter, use a suitable illustration

29. Explain the operation principles of a galvanometer, use a suitable illustration

30. Explain the operation principle of megger, use a suitable illustration

Answer 1