Draw a schematic sketch of a moving coil galvanometer and describe briefly its working.
Solution
Working principle of the moving coil galvanometer
When a current flows through the coil, a torque acts on it. The magnetic torque tends to rotate the coil. A spring provides a counter torque that balances the magnetic torque resulting in a steady angular deflection .
Construction of a moving coil galvanometer
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The galvanometer consists of a coil, with many turns, free to rotate about a fixed axis, in a uniform radial magnetic field. There is a cylindrical soft iron core which not only makes the field radial but also increases the strength of the magnetic field.When a current flows through the coil, a torque acts on it.The magnetic torque tends to rotate the coil. A spring provides a counter torque that balances the magnetic torque, resulting in a steady angular deflection. The deflection is indicated on the scale by a pointer attached to the spring.
Working principle of the moving coil galvanometer
When a current flows through the coil, a torque acts on it. The magnetic torque tends to rotate the coil. A spring provides a counter torque that balances the magnetic torque resulting in a steady angular deflection .
Construction of a moving coil galvanometer
The galvanometer consists of a coil, with many turns, free to rotate about a fixed axis, in a uniform radial magnetic field. There is a cylindrical soft iron core which not only makes the field radial but also increases the strength of the magnetic field.When a current flows through the coil, a torque acts on it.The magnetic torque tends to rotate the coil. A spring provides a counter torque that balances the magnetic torque, resulting in a steady angular deflection. The deflection is indicated on the scale by a pointer attached to the spring.