Question

An ammeter and a voltmeter are connected in series to a battery with an emf `xi = 6.0 V`. When a certain resistance is connected in parallel with the voltmeter, the readings of the latter decreases `eta = 2.0` times, whereas the readings of the ammeter increase the same number of times, Find the voltmeter readings after the connection of the resistance.

Answer 1

Let `R=` resistance of ammeter

Potential difference across voltmeter `=6-` potential difference across ammeter
In first case, `V=6-iR` …………i
In second case, `V/2=6-(2i)R` ……………ii
solving these two equations we get
`V=4`volt
`:. V/2=2` volt