JEE MAIN - Physics (2020 - 8th January Evening Slot - No. 16)

A galvanometer having a coil resistance 100 $$\Omega $$ gives a full scale deflection when a current of 1 mA is passed through it. What is the value of the resistance which can convert this galvanometer into a voltmeter giving full scale deflection for a potential difference of 10 V?
8.9 k$$\Omega $$
10 k$$\Omega $$
9.9 k$$\Omega $$
7.9 k$$\Omega $$

Explanation

ig = 1 mA , Rg = 100 $$\Omega $$

V = ig(R + Rg)

$$ \Rightarrow $$10 = 1 Ɨ 10–3 (R + 100)

$$ \Rightarrow $$R = 9.9 k$$\Omega $$

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