• Rectangular copper coil
• Suspension wire
• Iron core
• Pointer (needle)
• Shunt 1. U — Shaped Permanent Magnet U- shaped permanent magnet with concave poles. 2. Rectangular Copper Coil Rectangular copper coil wound on a frame of some non - magnetic material. 3. Suspension Wire Suspension wire, which also severs as current lead. Its other end is connected to a spiral, which serves as second currentlead. 4. Iron Core Presence of iron cylinder increases the magnetic field between the pole and the lines of forces remain parallel. 5. Pointer Aluminum pointer attached to a pivoted coil, to read the deflection. 6. Shunt It is a high value resistance connected in series with the coil of galvanometer. Working When current is allowed to pass through the meter most of the potential drop will take place across the high resistance whose value is so adjusted that the remaining potential difference across the galvanometer causes current which gives full scale deflection of the galvanometer. Principle According to Ohm’s law the potential difference across a resistance is directly proportional to the current passing through it. Therefore the deflection in the galvanometer is directly proportional to the potential difference applied across the terminal of the galvanometer. Conversion of Galvanometer into Volt Meter To convert galvanometer into voltmeter, a wire of high resistance is connected in series to the coil of galvanometer. Connection in Circuit In order to measure the potential difference of a resistor a voltmeter is always connected in parallel to the source.
No comments:
Post a Comment
Dont paste link here..