Chapter 10, Problem 45P

A child's electronic toy is supplied by three 1.58-V alkaline cells having internal resistances of 0.0200 $\Omega$ inseries with a 1.53-V carbon-zinc dry cell having a 0.100- $\Omega$ internal resistance. The load resistance is 10.0 $\Omega$ . (a) Draw a circuit diagram of the toy and itsbatteries, (b) What current flows? (c) How much power is supplied to the load? (d) What is the internal resistance of the dry cell if it goes bad, resulting in only 0.500 W being supplied to the load?