Question

EXAMPLE 25. When two identical batteries of internal
resistance 1 ohm each are connected in series across a resistor
R, the rate of heat produced in Ris J. When same batteries
are connected in parallel across R, the rate of heat
production is J. If J1 = 2.25 J2. Find the value of R(IIT, 2010)
th​

Answer 1

this is the final answer not complete solution which I have putted it....

2(r+2R)=3(2r+R)

2r+4R=6r+3R

R=4r=4Ω Answer