The principle of operation of LVDT is based on the variation ofa) Conductanceb) Reluctancec) Inductanced) Capacitance

The principle of operation of the Linear Variable Differential Transformer (LVDT) is based on the variation of:

c) Inductance

Here's a step-by-step explanation:

1. The LVDT is a type of electromechanical transducer that can convert the rectilinear motion of an object to which it is coupled mechanically into a corresponding electrical signal.

2. The LVDT operation does not require an electrical contact between the moving part (probe or core assembly) and the coil assembly, but instead relies on electromagnetic coupling.

3. The LVDT has a primary coil and two secondary coils wound on a cylindrical former. These coils are connected in series but opposite in phase. The primary coil is energized with an AC supply.

4. When the core is in the central position, the voltages induced in both secondary coils are equal but opposite in phase. Therefore, the output voltage is zero.

5. When the core is displaced from the null position, the voltage in one coil increases while it decreases in the other. The output voltage is the difference between the two voltages, which is proportional to the displacement of the core.

6. The direction of the output voltage indicates the direction of the displacement.

7. The variation in the magnetic coupling between the primary and the two secondary coils, due to the displacement of the core, results in a variation in the inductance of the secondary coils. This is why the operation of the LVDT is based on the variation of inductance.