A sensitive galvanometer has a resistance of 180 $\Omega$ and requires 2.4 $\mu$A of current to produce a full-scale deflection.The shunt resistance needed to construct an ammeter that gives full-scale deflection for a current of 1.0 mA is approximately
A)4.5 $\Omega$
B)0.43 $\Omega$
C)0.22 $\Omega$
D)0.86 $\Omega$
E)1.72 $\Omega$

Question

Quizplus · Accepted Answer

To convert a galvanometer to an ammeter, a shunt resistor (Rs) is connected in parallel with the galvanometer. The value of Rs can be calculated using the formula: Rs = (Rg * Ig) / (I - Ig), where Rg is the resistance of the galvanometer, Ig is the current for full-scale deflection of the galvanometer, and I is the total current for the ammeter's full-scale deflection. Substituting the given values (Rg = 180 ohms, Ig = 2.4 μA = 0.0024 mA, I = 1.0 mA), Rs = (180 * 0.0024) / (1.0 - 0.0024) ≈ 0.43 ohms.

A Sensitive Galvanometer Has a Resistance of 180 Ω\OmegaΩ And Requires 2

A Sensitive Galvanometer Has a Resistance of 180 $\Omega$ And Requires 2