The potential difference across resistance R carrying current I is V = IR . Now if the potential difference is measured via voltmeter of resistance r , the reading on voltmeter is V' . Prove that V' = Ir/(R+r) . For what value of r does the voltmeter measure true value
The Attempt at a Solution
Initially , V = IR
FINALLY, Rnet = R × r / ( R + r)
V' = I' Rnet , where I' is telhe new current in circuit..
I don't know how to proceed