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MHT CET · Physics · Current Electricity

A galvanometer of resistance ' \(G\) ' is shunted by a resistance of \(5 \Omega\). To keep the main current in the circuit unchanged, the resistance to be put in series with the same galvanometer is

  1. A \(\frac{\mathrm{G}^2}{\mathrm{~S}+\mathrm{G}}\)
  2. B \(\frac{5 G}{S+G}\)
  3. C \(\frac{G}{S+G}\)
  4. D \(\frac{S^2}{S+G}\)
Verified Solution

Answer & Solution

Correct Answer

(A) \(\frac{\mathrm{G}^2}{\mathrm{~S}+\mathrm{G}}\)

Step-by-step Solution

Detailed explanation

Current will be unchanged if resistance remains same to
\(\begin{aligned} & G=\frac{G S}{G+S}+R \\ & \Rightarrow R=G-\frac{G S}{G+S}=\frac{G^2}{G+S}\end{aligned}\)