Two identical batteries each of emf `E= 2`volt and internal resistance `r=1` ohm are available `t`. produce heat in an external resistance by passing a current through it. What is the maximum power that can be developed across an external resistance `R` using these batteries?

Answer

B

Explanation

As derived in the above question
`P_(max)=E^2/(4r)`
here, `E =` net emf `= 2+2=4V`
and `r =` net internal resistance
`=1+1=2Omega`
`:. P_(max)=((4)^2)/((4)(2))=2W`