JEE Main 2018PhysicsCurrent ElectricityEasyMCQ

JEE Main 2018 — Current Electricity Question with Solution

JEE Main 2018 (16 Apr Online)

Question

A galvanometer with its coil resistance 25 Ω requires a current of 1 mA for its full deflection. In order to construct an ammeter to read up to a current of 2 A the approximate value of the shunt resistance should be:

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Show full solutionCorrect option: A
Correct answer
A1.25 ×10-2 Ω

Step-by-step explanation


From the above figure, it is clear that, IgRg=(I- Ig)S
S ≃10-3×252⇒S ≃12.5 ×10-3
⇒1.25 ×10-2Ω

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About this question

This is a previous-year question from JEE Main 2018, covering the Current Electricity chapter of Physics. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.