c) Birefringent Hence the voltages induced into these windings are of opposite polarities. c) 0.5 to 1.0 Ans : (d) High Sensitivity: The LVDT has a high sensitivity of about 300 mV/mm. This provides an infinite mechanical life to an LVDT. Which of the following can be measured with the help of piezo electric crystal? c) Reluctance The output of the LVDT is AC signal, therefore, a demodulator network must be used if a DC output is required. 4. Handle all equipments with care. ________ fiber is used in interferometric instruments. c) Second electrode As the primary is connected to an AC source so alternating current and voltages are produced in the secondary of the LVDT. c) Digital transducers d) Inverse. The output is obtained due to the difference between voltages on the secondary coil and it measures the linear displacement, therefore it called a Linear Variable Differential Transformer. a) Monomode As we can see that a Linear variable differential transformer is composed of a primary winding P 0 along with 2 secondary windings S 0 and S 1. c. Linearly with the linear displacement. c) S1 is false and S2 is true When the core is moved off center, the voltage in the secondary toward which the core is moved increases, while the opposite voltage decreases. It posses high sensitivity, typically about 40 V/mm. 37. An inverse transducer is a device which converts, a) An electrical quantity into a non electrical quantity c) Diameter of wire The linear variable differential transformer has three solenoidal coils placed end-to-end around a tube. b) Silver electrode b. Angular displacement. d) Both S1 & S2 are false, 27. Resistance Temperature Detector Working Principle, Piezoelectric Transducer Working Principle. 1810V, 40V c. 1820V, 30V d. 1825V, 15V View Answer / Hide Answer It gives higher output for small change in magnetic core position. Some of the advantages of LVDT are given below. d) Blood flow in heart lung machine, 35. In a LVDT, the two secondary voltages a) Are independent of the core position b) Vary unequally depending on the core position c) Vary equally depending on the core position d) Are always in phase quadrature Ans : (b) 28. Required fields are marked *. LVDT Working Principle. a. c) Coupling of two coils changes with displacement The LVDT has high sensitivity. d) Stable action potential, 45. The size of air cored transducers in comparison to the iron core parts is, a) Smaller d) LVDT, 5. b) Analog transducer 27. b) Digital plethysmography On our position measurement LVDTs, the two transducer secondaries are connected in opposition. Ans : (b) ... AC Circuits Multiple Choice Questions. Both the secondary windings (S1 & S2) has an equal number of turns and placed identically on either side of the primary winding in such a way that the net output will be the difference of the voltage of both secondary windings. b) Inductive d) Fiber group. Other causes of residual voltage are stray magnetic fields and temperature effects. a) Mechanical force An LVDT is also known as Linear Voltage Differential Transformer is a passive transducer which translates the linear motion into an electrical signal. Linear inductance. S2: Transducer is also called as sensor. b) Primary sensor Under normal condition of RVDT, the flux linkage of both the secondary winding are same due to their symmetrical placing w.r.t. Q1) The detectors used in optical sensors is ... the mutual inductance between the primary and secondary coils varies. Your email address will not be published. When the core is centrally located, the net voltage is zero. Pressure transducer for measuring blood pressure is, a) Strain gauge transducer only ... (mm) 1. The change in resistance of a metal wire owing to strain is due to. d) S1 only, a) Steel sheets Cadmium and sulphate, a) 1,2 and 4 24. In an LVDT, a complete isolation exists between input and output. Such materials are called, a) Piezo-electric d) Copper, 20. S Bharadwaj Reddy November 3, 2016 November 3, 2017. LVDT consists of one primary winding P and two secondary windings S1 & S2 mounted on a cylindrical former. a) Strain gauge c) Analog transducers S Bharadwaj Reddy January 1, 2015 … Secondary 1 + Secondary 2 The transfer of current between the primary and the secondaries of the LVDT displacement transducer is controlled by the position of a magnetic core called an armature. The transfer characteristic of LVDT is shown in the figure. a) Force The center coil is the primary, and the two outer coils are the top and bottom secondaries. b) Encoder c) Dialysate flow in artificial kidney 3. The linear variable differential transformer transducer is A. Inductive transducer B. Non-inductive transducer C. Capacitive transducer D. Resistive transducer ... ANSWER: D. All of these . b) 25 micron (or) less d) Pressure. The primary winding is connected to an AC voltage source. Figure 9. d) 2,3and 4, a) Passive transducers When the core is centered, the voltages in the two secondary windings oppose each other, and the net output voltage is zero. 16. A movable soft iron core is placed inside the former. Fig 3: As the core moves, the relative coupling and signal output voltage of the two secondary windings changes. In addition, there is a change in phase with respect to the source when the core is moved to one side or the other. b) Dynamic In a LVDT, the two secondary voltages, a) Are independent of the core position The secondary coils are connected in series to measure the sum of output voltage and derive the … Ans : (b) 29. Q11. The LVDT (see Figure 15.3.2) is a position-to-electrical sensor whose output is proportional to the position of a movable magnetic core.The core moves linearly inside a transformer consisting of a center primary coil and two outer secondary coils wound on a cylindrical form. c) Ferrite a) S1 is true and S2 is false Let us assume that the secondary voltage of the RVDT transformer is Es21 and Es22, respectively. d) Excitation voltage, 9. b) Blood flow Strain gauge, LVDT and thermocouple are examples of, a) Active transducers b) When radiant energy stimulates the crystal Figure 1: Linear variable differential transformer (LVDT) The secondary windings are wound out of phase with each other. Q7) Potentiometer is used for the measurement of. i.e., 1mm displacement of the care produces an output voltage of 300 mV. ... As the core is moved in one direction from the null position, the differential voltage i.e., the difference of two secondary voltages, will increase while maintaining an in-phase relationship with the voltage from the input source. 14. It can … c) Both S1 & S2 are true d) Resistance, a) 1 Photo emissive cathode & 2 dynodes d) Eddy current. In a LVDT, the two secondary voltages. When the magnetic core moves up word the induced voltage in secondary winding S1 is increased while the voltage in S2 are decreased and the net output voltage E1 – E2. Fig: LVDT cross-section (source: te.com ) Linear Variable Differential Transformer (LVDT) is an inductive transducer that we discussed in the previous article. Magnetic flux produced by the primary is coupled to the two secondary coils, inducing an AC voltage in each coil. EEG A. d) Permanence, a) Magneto-strict ion ... Due to this magnetic field, an ac voltage gets induced in the two secondary windings. Ideally, the output voltage at the null position should be equal to zero. If at one end, the two wires made of different metals are joined together then a voltage will get produced between the two wires due to difference of temp between the two ends of wires. c) Force into a displacement b) 2 Photo emissive cathodes & 2 dynodes S1: In multimode fiber optics, intensity modulating schemes can be employed. The LVDT’s electrical output signal is determined by the relative differential AC voltage between the two secondary windings, which varies with the linear position of the core within the LVDT coil (Figure 3 center). c) Digital transducer b) 1.5 to 2.0 c. Mutual inductance. 50. LVDT Construction 2. ... wire) configurations. GRAPH: RESULT: - Graph between voltage and displacement is plotted. d) Primary transducers, 6. It is a passive type sensor. 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