Current Electricity and Electrical InstrumentMedium
Question
In the circuit shown, reading of the voltmeter connected across 400 Ω resistance is 30 V. If it is connected across 300 Ω resistance then reading will be
Options
A.45 V
B.32.5 V
C.22.5 V
D.18 V
Solution
Case - I 
current I =
amp I1 = 
amp
30 = (I - I1)RV ⇒ RV =
= 1200Ω
Case = II
I =
= 
amp.
I0 300 = (I − I0) 1200 ⇒ I0 =
I = 
amp
Reading of voltmeter
× 300 = 
= 22.5 V
current I =
amp I1 = amp30 = (I - I1)RV ⇒ RV =
= 1200ΩCase = II
I =
= amp.I0 300 = (I − I0) 1200 ⇒ I0 =
I = ampReading of voltmeter
× 300 = = 22.5 VCreate a free account to view solution
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