Ammeter sensitivity is the amount of current necessary to cause full scale deflection (maximum reading) of the ammeter. The smaller the amount of current, the more "sensitive" the ammeter. For example, an ammeter with a maximum current reading of 1 milliampere would have a sensitivity of 1 milliampere, and be more sensitive than an ammeter with a maximum reading of 1 ampere and a sensitivity of 1 ampere. To decrease the range of an ammeter we need to change it's sensivity, so that's why it is impossible.
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Just have a question. Do you also provide help in understanding a concept? Not an assignment but for my learning. If certain concepts in the book are not clear, can you provide a simplified explanation of it using math that's understandable? You can charge the equivalent of an assignment.
Some things in the chapter attachments I sent you are not clear. They do not have much solved examples either.
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