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A galvanometer of coil resistance 90 ohm gives full-scale deflection at 10 mA. A 910 ohm resistor is put in series to convert it into a voltmeter. If the least count of this voltmeter is 0.1 V, how many divisions are on its scale?

100
90
91
none

Correct answer: 100

Solution

Full-scale voltage = 0.01*1000 = 10 V; number of divisions = 10 V / 0.1 V = 100.

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