Vernier calliperA Vernier caliper is a device used to measure the distance between two opposing sides ofan object. The vernier, dial, and digital calipers give a direct reading of the distancemeasured to high accuracy. They are functionally identical, with different ways of readingthe result. These calipers comprise a calibrated scale with a fixed jaw, and another jaw,with a pointer, that slides along the scale. The distance between the jaws is then read indifferent ways for the three types.A Vernier Caliper is used in many fields such as metalworking, mechanicalengineering, gunsmithing, handloading, woodworking, woodturning and in medicine.Screw gaugeMeasures the thickness of the glass plate, diameter of the metal wire, volume of the givenglass plate.Apparatus: Screw Gauge, Glass Plate and Metal wire.Screw Gauge consists of a U shaped metallic frame. To one side of this U frame a longhallow cylindrical tube with a nut inside it, the inner side of the cylindrical nut contains auniform thread cut in it. On the other side of the U frame a fixed stud with a plane faceis attached.GalvanometerA galvanometer is a type of ammeter: an instrument for detecting and measuring electriccurrent. It is an analog electromechanical transducer that produces a rotary deflection ofsome type of pointer in response to electric current flowing through its coil. The term hasexpanded to include uses of the same mechanism in recording, positioning,and servomechanism equipment.AmmeterAn ammeter is a measuring instrument used to measure the electric current in a circuit.Electric currents are measured in amperes (A), hence the name. Instruments used tomeasure smaller currents, in the milliampere or microampere range, are designatedas milliammeters or microammeters. Early ammeters were laboratory instruments whichrelied on the Earths magnetic field for operation.