Question
A voltmeter of resistance 20000 Ω reads 5 volt. To make it read 20 volt, the extra resistance required is
40000 Ω in parallel
60000 Ω in parallel
60000 Ω in series
40000 Ω in series
Solution
C.
60000 Ω in series
⇒ R = 3 G
= 3 × 20000
⇒ R= 6000
Extra resistance = 60000 Ω in series