A galvanometer of resistance 3663 Ω gives full scale deflection for a certain current Ig. The value of the resistance of the shunt which when joined to the galvanometer coil will result in 1/34 of the total current passing through the galvanometer is
(A) is correct. If only 1/34 of total current passes through the galvanometer, then shunt resistance
Rs = Rg/33 = 3663/33 ≈ 111Ω, which is closest to 100 Ω. So, option (A) is correct.
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Let the shunt resistance be
Rs and galvanometer resistance be
Rg = 3663Ω
Given: only 1/34 of total current I passes through the galvanometer.
Using current division rule:
Ig/Is = Rs/Rg ‘ Where Ig/I = 1/34’ ⇒ Is/I = 33/34
So:
1/33 = Rs/3663 ⇒ Rs = 3663/33 = 111 Ω ≈100Ω
Answer: (A) 100 Ω.