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Strain Gauge: Working Principle & Diagram

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  What is a Strain Gauge A strain gauge is a resistor used to measure strain on an object. When an external force is applied on an object, due to which there is a deformation occurs in the shape of the object. This deformation in the shape is both compressive or tensile is called strain, and it is measured by the strain gauge. When an object deforms within the limit of elasticity, either it becomes narrower and longer or it become shorter and broadens. As a result of it, there is a change in resistance end-to-end. The strain gauge is sensitive to that small changes occur in the geometry of an object. By measuring the change in resistance of an object, the amount of induced stress can be calculated. The change in resistance normally has very small value, and to sense that small change, strain gauge has a long thin metallic strip arrange in a zigzag pattern on a non-conducting material called the carrier, as shown below, so that it can enlarge the small amount of stress in the grou...

SYLLABUS FOR SELECTION TO THE POST OF SUB-ENGINEER (ELECTRICAL) IN KSEB

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FURTHER DETAILS REGARDING MAIN TOPICS OF PROGRAMME NO. 08B/2015 (Item Nos. 7, 8 & 9)   SUB ENGINEER (ELECTRICAL) (NCA Notification)   KERALA STATE ELECTRICITY BOARD (CATEGORY NO. 325/2011, 326/2011 & 327/2011)     PART I: ELECTRICAL ENGINEERING     BASIC ELECTRICAL ENGINEERING   Electrical Circuits and Networks   Electric current, Voltage, Resistance- Definition and units, Laws of resistance- Sp: resistance- Conductance and Conductivity, Effect of temperature on resistance- Temp. coefficient. D. C. Circuits- Ohm’s law- series, parallel, series- parallel circuits.   Network theorems- Kirchoff’s Law, Super position theorem, Thevenin’s theorem, Norton theorem- Electric power and Energy in DC circuits, their units etc. Heating effect of electric current- Joules law   Electrostatics      Magnetism   Static electricity- Absolute and relative permittivity of a...