Derive the expressions for the ratio and phase angle errors of a current transformer ... Draw the equivalent circuit and phasor diagram of a PT. Deriv...
a. Classify the types of instruments b. Explain the constructional details of PMMC instrument with neat sketch. 2. Explain the various operating forces needed for proper operation of an analog indicating instrument. 3. a. Explain the constructional details and operation of MI instruments b. Derive the Torque equation for Moving iron Instruments. 4. a. Derive the expressions for the ratio and phase angle errors of a current transformer b) Explain the following terms i) Actual Ratio ii) Nominal ratio iii) Ratio correction factor iv) Burden of an instrument transformer 5. Write about extension of range of ammeters and voltmeters 6. a. Draw the equivalent circuit and phasor diagram of a PT. Derive the expression for its ratio and phase angle errors. b. Explain the meaning of burden in instrument Transformer 7.a. Derive the equation for deflection os a Dynamometer type of instruments which can be used for both DC and AC. b. What are the advantages of Instrument Transformers over Ammeter shunts and Voltmeter multipliers?
1. (a) Show that the power in a 3-phase system is measured by the use of i. Only one watt meter and
ii. Two watt meters.
(b) Explain the constructional details of LPF Watt Meter 2. Explain the construction and working of a single phase induction type energy meter. Show that the total number of revolutions made by its disc during a particular time is proportional to the energy consumed. 3.
a) Explain with a neat circuit of Dynamometer type Wattmeter and derive the equation for deflection.
b) List the various types of errors in dynamometer type Wattmeter’s. 1. Explain how an unknown voltage can be measured by using a polar type potentiometer? 2. a) List the steps when D.C. crompton’s potentiometer is used to measure an unknown resistance with neat diagram?