A potentiometer having the potential gradient of $2\ mV/cm$ is used to measure the difference of potential across a resistance of $10\ ohm.$ If a length of $50\ cm$ of the potentiometer wire is required to get the null point, the current passing through the $10\ ohm$ resistor is (in $mA$)

Question

Dr. Abubacker · Accepted Answer

(d) $V = xl \Rightarrow iR = xl$
$\Rightarrow i 	imes 10 = \left( \frac{2 	imes 10^{- 3}}{10^{- 2}} ight) 	imes 50 	imes 10^{- 2} = 0.1$
$\Rightarrow i = 10 	imes 10^{- 3}A = 10\ mA$

Q. A potentiometer having the potential gradient of $2\ mV/cm$ is used to measure the difference of potential across a resistance of $10\ ohm.$ If a length of $50\ cm$ of the potentiometer wire is required to get the null point, the current passing through the $10\ ohm$ resistor is (in $mA$)

Explanation

Reviewed by Dr. Abubacker

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