Question

Interactive Solution 20.47 provides one approach to problems like this one. Three resistors are connected in series across a battery. The value of each resistance and its maximum power rating are as follows: 5.0Ω and 24.5 W, 38.3Ω and 12.0 W, and 13.4Ω and 13.9 W. (a) What is the greatest voltage that the battery can have without one of the resistors burning up? (b) How much power does the battery deliver to the circuit in (a)?

Answer 1

(a)

Current is related to the power and resistance as

Maximum current allowed for each resistance is

In series same current passes through all the resistance, the voltage across the battery should be such that it does not deliver current more than 0.5597A, or else the second resistance will fuse.

The total resistance of the circuit is

The voltage across battery is

(b)

The power delivered by the battery is