SSE JE Electrical Engineering 29 Oct 2020 Shift 2 Papers

To increase the ranges of a voltmeter, we need to connect a high multiplier resistance in series with voltmeters.
To increase the range of a voltmeter, we need to the series resistance and it is given by
${\mathrm{R}}_{\mathrm{se}}={\mathrm{R}}_{\mathrm{m}}\left(\frac{\mathrm{V}}{{\mathrm{V}}_{\mathrm{m}}}-1\right)$
Where V is the required voltmeter range
${\mathrm{V}}_{\mathrm{m}}$ is the voltmeter range
${\mathrm{R}}_{\mathrm{m}}\mathit{­}$ is the meter internal resistance