Question

A voltmeter is connected across a battery of emf 12.0 V and internal resistance of 10 Ω. If the voltmeter resistance is 230 Ω, what reading will be shown by voltmeter?

Answer 1

emf=I(R+r) (where  R is resistance and r is internal resistance)

=>12/240=I

=>I=0.05A

We know that,

V=IR

=>V=0.05*230=11.5V

Answer 2

Ans: In case i)
V=12V , R = 10 Ω ,
=> V = I R
=> 12 = I x 10
=> I = 1.2 Ampere.

In case ii)
R = 230 Ω , I = 1.2 A
=> V = 230 x 1.2
=> V = 276 V

Hope it helps...!!