Q 21 :

When a resistance of 5Ω is shunted with a moving coil galvanometer, it shows a full scale deflection for a current of 250 mA; however, when 1050Ω resistance is connected with it in series, it gives full scale deflection for 25 volt. The resistance of the galvanometer is ______ Ω.                 [2023]



(50)

250mA×55+RG=i                             ...(i)

i=251050+RG                             ...(ii)

From (i) and (ii),

251050+RG=54(5+RG)

100(5+RG)=1050×5+RG×5

95RG=4750    RG=50Ω



Q 22 :

A moving coil galvanometer of resistance 100 Ω shows a full scale deflection for a current of 1 mA. The value of resistance required to convert this galvanometer into an ammeter, showing full scale deflection for a current of 5 mA, is ________ Ω                       [2026]

  • 0.5

     

  • 10

     

  • 2.5

     

  • 25

     

(4)