Ncert Exercises & Solutions

A multirange current meter can be constructed by using a galvanometer circuit as shown in the figure. We want a current meter that can measure 10mA, 100mA, and 1A using a galvanometer of resistance 10Ω, and that produces maximum deflection for a current of 1mA. Find $S_{1}, S_{2}, and S_{3}$ that have to be used.

Hint: The potential drop in the galvanometer and the shunt will be the same.

Step 1 : I_{G} \cdot G = (I_{1} - I_{G}) (S_{1} + S_{2} + S_{3}) for I_{1} = 10 mA

Step 2 : I_{G} (G + S_{1}) = (I_{2} - I_{G}) (S_{2} + S_{3}) for I_{2} = 100 mA

Step 3 : I_{G} (G + S_{1} + S_{2}) = (I_{3} - I_{G}) (S_{3}) for I_{3} = 1 A

Gives S_{1} = 1 W, S_{2} = 0 .1 W

and, S_{3} = 0 .01 W

NEET Information

courses

Company

Botany Questions

Chemistry Questions

Physics Questions

Zoology Questions