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UPPCL JE Electrical 27 November 2019 (Shift 2)

Option 3 : 9950 Ω

UPMRC (LMRC) SCTO Psycho Aptitude Full Test 1

2007

111 Questions
101 Marks
35 Mins

Concept:

To increase the range of a voltmeter, we need to the series resistance and it is given by

\({R_{se}} = {R_m}\left( {\frac{V}{{{V_m}}} - 1} \right)\)

Where V is the required voltmeter range

Vm is the voltmeter range

Rm is the meter internal resistance

Calculation:

Given that,

Meter full scale current reading (Im) = 1 mA

Internal resistance (Rm) = 50 Ω

Voltmeter range (Vm) = Im Rm = 1 × 10-3 × 50 = 0.05 V

Required voltmeter range (V) = 10 V

\({R_{se}} = 50\left( {\frac{{10}}{0.05} - 1} \right) = 9950\;{\rm{Ω }}\)