JEE Mains · Physics · STD 12 - 4. Moving charges and magnetism
A galvanometer having a coil of resistance \(30 \Omega\) need 20 mA of current for full-scale deflection. If a maximum current of 3 A is to be measured using this galvanometer, the resistance of the shunt to be added to the galvanometer should be \(\frac{30}{X} \Omega\), where \(X\) is ________.
- A 596
- B 149
- C 298
- D 447
Answer & Solution
Correct Answer
(B) 149
Step-by-step Solution
Detailed explanation
\(\begin{aligned} & \left(I-I_g\right) R=I_g G \\ & (3-0.02) \times R=0.02 \times G \Rightarrow R=\frac{30}{149} \\ & \Rightarrow 149=\text { Required } X\end{aligned}\)
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