1)

A galvanometer having a coil resistance of 100 Ω gives a full-scale deflection when a current of 1 mA is passed through it. The value of the resistance which can convert this galvanometer into ammeter giving a full-scale deflection for a current of 10 A is 


A) 0.01Ω

B) 2Ω

C) 0.1Ω

D) 3Ω

Answer:

Option A

Explanation:

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 In parallel, current distributes in inverse ratio of resistance

 Hence,  llglg=GSS=GIgIIg

As Ig is very small, hence    S=GIgI

 b=(100)(1×103)10=0.01 Ω