A sensitive galvanometer has a resistance of 180 $\Omega$ and requires 2.40 $\mu$A of current to produce a full-scale deflection.The series resistance needed to construct a voltmeter that gives full-scale deflection for a potential difference of 10.0 V is approximately
A)4.17 M$\Omega$
B)180 $\Omega$
C)1.80 k$\Omega$
D)8.33 M$\Omega$
E)2.08 M$\Omega$

Question

Quizplus · Accepted Answer

To convert the galvanometer into a voltmeter that can measure up to 10.0 V, we need to calculate the series resistance required. The formula for the total resistance in a series circuit is $R_{total} = R_{galvanometer} + R_{series}$. The voltage across the galvanometer is $V = I \times R_{galvanometer}$, where $I = 2.40 \mu A$ and $R_{galvanometer} = 180 \Omega$. To find $R_{series}$, we use $V_{total} = I_{total} \times R_{total}$, where $V_{total} = 10.0 V$. Rearranging for $R_{series}$ and substituting the given values, we find that $R_{series}$ is approximately 4.17 M$\Omega$, which matches choice A.

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