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Question
Figure shows two circuits each having a galvanometer and a battery of 3V.
When the galvanometers in each arrangement do not show any deflection, obtain the ratio R1/R2.
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Solution
For balanced wheat stone bridge, there will be no deflection in the galvanometer.
`4/R_1 = 6/9 => R_1 =(4 xx 9)/6 = 6Ω`
For the equivalent circuit, when the wheat stone bridge is balanced, there will be no deflection in the galvanometer.
`therefore 12/8 = 6/R_2 => R_2 \ ( 6xx 8)/12 = 4 Ω`
`therefore R_1/R_2 = 6/4 = 3/2`
RELATED QUESTIONS
The combined resistance of a galvanometer of resistance 500Ω and its shunt is 21Ω. Calculate the value of shunt.
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A galvanometer has a resistance of 16Ω. It shows full scale deflection, when a current of 20 mA is passed through it. The only shunt resistance available is 0.06 which is not appropriate to convert a galvanometer into an ammeter. How much resistance should be connected in series with the coil of galvanometer, so that the range of ammeter is 8 A?
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A galvanometer of resistance 100 Ω gives a full-scale deflection for a current of 10−5 A. To convert it into an ammeter capable of measuring up to 1 A we should connect a resistance of ______.
A galvanometer having a resistance of 20 Ω and 30 Ω division on both sides has figure of merit 0.005 ampere/division. The resistance that should be connected in series such that it can be used as a voltmeter upto 15 volt, is ______.
A moving coil galvanometer has 150 equal divisions. Its current sensitivity is 10-divisions per milliampere and voltage sensitivity is 2 divisions per millivolt. In order that each division reads 1 volt, the resistance in ohms needed to be connected in series with the coil will be ______.
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Reason: A circular coil produces a uniform magnetic field around itself when an electric current is passed through it.
