A millivoltmeter with range 25 mV is to be used as an ammeter with range 25 A. Find the required shunt resistance in ohms.
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A millivoltmeter with range 25 mV is to be used as an ammeter with range 25 A. Find the required shunt resistance in ohms.

G1 Physics · Accepted Answer

Step 1: The conversion requires a very small resistance in parallel so total 25A corresponds to 25mV voltage drop. Step 2: By Ohm's law, effective shunt resistance R≈V/I. Step 3: R=25mV/25A=(25×10⁻³)/25=10⁻³Ω=0.001Ω. Answer A. Final answer: (A) 0.001.