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Question
The reduction factor K of a tangent galvanometer is written on the instrument. The manual says that the current is obtained by multiplying this factor to tan θ. The procedure works well at Bhuwaneshwar. Will the procedure work if the instrument is taken to Nepal? If there is same error, can it be corrected by correcting the manual or the instrument will have to be taken back to the factory?
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Solution
Yes, the procedure will work if the instrument is taken to Nepal, as the current at a place can be calculated by multiplying the reduction factor K with tan θ of that place . In our case, we will take the value of tan θ of Nepal, as tan θ may vary from place to place. tan θ at any place is determined from the mathematical formula `B/B_H` , where B is the external magnetic field and `B_H` is the horizontal component of Earth's magnetic field Thus, we need not take the manual or the instrument back to the factory for correction.
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