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Hi; Could someone please help me with the following question: If the restoring spring of a galvanometer weakens by 26.4% over the years, what current will give full-scale deflection if it originally required 36.8uA? Thanks for your help.
You need to make some assumption here about the construction of a galvanometer. I am going to assume you have an ideal case where the angular deflection of the needle is directly proportional to the current because the magnetic field is constructed to achieve that condition, as illustrated hereJodi said:Hi; Could someone please help me with the following question: If the restoring spring of a galvanometer weakens by 26.4% over the years, what current will give full-scale deflection if it originally required 36.8uA? Thanks for your help.
No. To have the same deflection angle, the product of k times I must not change. If k is reduced by some fraction, the current is going to have to increase. Let k' and I' be the "new" values for the weakened spring and k and I be the "old" values that gave the same deflection. ThenJodi said:Are you saying to do 0.264 x 36.8E-6? Because that doesnt give me the right answer. Thanks.