Moving Charges and Magnetism - Result Question 85

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87. A galvanometer of resistance $20 \Omega$ gives full scale deflection with a current of $0.004 A$. To convert it into an ammeter of range $1 A$, the required shunt resistance should be

======= ####87. A galvanometer of resistance $20 \Omega$ gives full scale deflection with a current of $0.004 A$. To convert it into an ammeter of range $1 A$, the required shunt resistance should be

3e0f7ab6f6a50373c3f2dbda6ca2533482a77bed:content/english/neet-pyq-chapterwise/physics/moving-charges-and-magnetism/moving-charges-and-magnetism—result-question-85.md (a) $0.38 \Omega$

(b) $0.21 \Omega$

(c) $0.08 \Omega$

(d) $0.05 \Omega$

[1996]

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Answer:

Correct Answer: 87. (c)

Solution:

  1. (c) Maximum current which can pass through galvanometer, $I_g=0.004 A$

Let $R$ be the resistance of shunt.

We know potential drop across $A B$

$=$ Potential drop across $C D$

$R(I-I_g)=I_g(20)$

$\Rightarrow R(1-0.004)=0.004 \times 20 \Rightarrow R=0.08 \Omega$