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प्रश्न
Why is it necessary to introduce a cylindrical soft iron core inside the coil of a galvanometer?
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उत्तर
The cylindrical soft iron core, when placed inside the coil of a galvanometer, makes the magnetic field stronger and radial in the space between it and pole pieces, such that whatever the position of the rotation of the coil is the magnetic field is always parallel to its plane.
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संबंधित प्रश्न
Why does a galvanometer show a momentary deflection at the time of charging or discharging a capacitor? Write the necessary expression to explain this observation.
With the help of a neat and labelled diagram, explain the principle and working of a moving coil galvanometer ?
Why does a galvanometer when connected in series with a capacitor show a momentary deflection, when it is being charged or discharged?
How does this observation lead to modifying the Ampere's circuital law?
Hence write the generalised expression of Ampere's law.
Outline the necessary steps to convert a galvanometer of resistance RG into an ammeter of a given range ?
Define the term ‘current sensitivity’ of a moving coil galvanometer.
The current sensitivity of a galvanometer is defined as ______.
The current sensitivity of a galvanometer increase by 20%. If its resistance also increases by 25%, the voltage sensitivity will ______.
A galvanometer having a coil resistance of 60 Ω shows full-scale deflection when a current of 1.0 amp passes through it. It can be converted into an ammeter to read currents up to 5.0 amp by:
A voltmeter of variable ranges 3 V, 15 V, 150 V is to be designed by connecting resistances R1, R2, R3 in series with a galvanometer of resistance G = 20 Ω, as shown in Fig. The galvanometer gives full pass through its coil for 1 mA current i.e. "gives full pass through it's coil for 1 mA current". Then, the resistances R1, R2 and R3 (in kilo ohms) should be, respectively:
