Current Electricity and Electrical InstrumentHard
Question
A microammeter has a resistance of 100Ω and full scale reange of μ A. It can be used as voltmeter or as higher range ammeter provided a resistance is added to it. Pick the correct range and resistance combination (s)
Options
A.50 V range with 10 k Ω resistance in series
B.10 V range with 200 k Ω resistance in series
C.5 mA range with 1Ω resistance in paallel
D.10 mA range with 1 Ω resistance in parallel
Solution
To increase the range of ammeter a parallel resistance (called shunt) is required which is given by
For option (c) S =
To change it in voltmeter, a high resistance R is put in series, where R is given by
R =
For option (b)
200kΩ
There, option (b) and (c).
For option (c) S =
To change it in voltmeter, a high resistance R is put in series, where R is given by
R =
For option (b)
200kΩThere, option (b) and (c).
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