Syllabus ,EM, Question papers, Answers, important Question ELECTRICAL MEASUREMENTS, R13 Regulation, B.Tech , JNTUK,Syllabus, download,
Measuring Instruments Classification – Deflecting, control and damping torques – Ammeters and Voltmeters – PMMC, moving iron type, dynamometer and electrostatic instruments – Expression for the deflecting torque and control torque – Errors and compensations– Extension of range using shunts and series resistance – CT and PT: Ratio and phase angle errors – Design considerations.
Measurement of Power and Energy Single phase and three phase dynamometer wattmeter – LPF and UPF – Expression for deflecting and control torques – Extension of range of wattmeter using instrument transformers – Measurement of active and reactive powers in balanced and unbalanced systems – Type of P.F. Meters – Single phase and three phase dynamometer and moving iron type Single phase induction type energy meter – Driving and braking. torques – errors and compensations –Testing by phantom loading using R.S.S. meter– Three phase energy meter – Tri vector meter – Maximum demand meters– Electrical resonance type frequency meter and Weston type synchroscope.
Potentiometers Principle and operation of D.C. Crompton’s potentiometer – Standardization – Measurement of unknown resistance – Current – Voltage – AC Potentiometers: polar and coordinate types –Standardization – Applications.
Measurements of Parameters Method of measuring low, medium and high resistance – Sensitivity of Wheat stone’s bridge – Carey Foster’s bridge– Kelvin’s double bridge for measuring low resistance– Loss of charge method for measurement of high resistance – Megger– Measurement of earth resistance – Measurement of inductance – Quality Factor – Maxwell’s bridge–Hay’s bridge – Anderson’s bridge–Measurement of capacitance and loss angle – Desautybridge – Schering Bridge–Wagner’s earthing device–Wien’s bridge.
Magnetic Measurements Ballistic galvanometer – Equation of motion – Flux meter – Constructional details–Determination of B–H Loop methods of reversals six point method – AC testing – Iron loss of bar samples– Core loss measurements by bridges and potentiometers.
Digital Meters Digital Voltmeter–Successive approximation – Measurement of phase difference – Frequency – Hysteresis loop using lissajious patterns in CRO – Ramp and integrating type–Digital frequency meter–Digital multimeter– Digital Tachometer.