A battery of internal resistance `3Omega` is connected to `20Omega` resistor and the potential difference across the resistor is 10V. If another resistor `30Omega` is connected in series with the first resistor and battery is again connectecl to the combination, then calculate the e.m.f and terminal potential difference across the combination..

Explanation

Case (i):
Terminal potential difference `V=(ER)/(R+r)`
i.e., `10=(E(20))/(20+3)`
`thereforeE=11.5V`
Case (ii) :
New terminal potential difference `V=(ER.)/(R.+r)=(11.5xx(20+30))/((20+30)+3)`
New terminal potential difference `V=(11.5xx50)/53=10.849` V.