A shunt extends the range of a 50-µA meter movement to 1 mA. How much is the current through the shunt at full-scale deflection?

Question

A shunt extends the range of a 50-[latex]\mu[/latex]A meter movement to 1 mA. How much is the current through the shunt at full-scale deflection?

Accepted Answer

All currents must be in the same units for Formula (12-2).

[latex]I_S=I_T-I_M[/latex] (12-2)

To avoid fractions, use 1000 [latex]\mu A[/latex] for the 1-mA [latex]I_T[/latex]. Then

[latex]I_S=I_T-I_M=1000\mu A- 50 \mu A[/latex]

[latex]I_S=950\mu A[/latex]

Question 12.1: A shunt extends the range of a 50-µA meter movement to 1 mA....