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MHT CET · Physics · Current Electricity

Two galvanometers ' \(A\) ' and 'B' require currents of \(4 \mathrm{~mA}\) and \(7 \mathrm{~mA}\), respectively to produce the same deflection of 20 divisions. If ' \(\mathrm{S}_{A}{ }^{\prime}\) and \({ }^{\prime} \mathrm{S} \mathrm{B}^{\prime}\) are their sensitivities,
respectively, then

  1. A \(\mathrm{S}_{\mathrm{A}}>\mathrm{S}_{\mathrm{B}}\)
  2. B \(\mathrm{S}_{\mathrm{A}}=\mathrm{S}_{\mathrm{B}}=\frac{4}{7}\)
  3. C \(\mathrm{~S}_{\mathrm{B}}=\frac{7}{4}=\mathrm{S}_{\mathrm{A}}\)
  4. D \(\mathrm{S}_{\mathrm{A}} < \mathrm{S}_{\mathrm{B}}\)
Verified Solution

Answer & Solution

Correct Answer

(A) \(\mathrm{S}_{\mathrm{A}}>\mathrm{S}_{\mathrm{B}}\)

Step-by-step Solution

Detailed explanation

(D)
\(\begin{aligned}
\text { sensitivity } \mathrm{S} &=\frac{\theta}{\mathrm{I}} \\
\frac{\mathrm{S}_{\mathrm{A}}}{\mathrm{S}_{\mathrm{B}}} &=\frac{\mathrm{I}_{\mathrm{B}}}{\mathrm{I}_{\mathrm{A}}}=\frac{7}{4} \\
\therefore \mathrm{S}_{\mathrm{A}}>\mathrm{S}_{\mathrm{B}} &
\end{aligned}\)