Question

Help with number 26 Holt Chapter 20 Practice problems? The diagram is above.

Practice problems■mm mmm-29.For thecircuit shown in Figure 20-39, determi 25. Find the equivalent resistance of the circuit shown e - a. the current in each resistor in Figure 20-36. (See Sample Problem 20C.) b. the potential difference across each resisto See Sample Problem 20D.) 30.0 V 6.0 Ω 18Ω 9.0 Ω 6.0Ω 9.0 Ω 12Ω Figure 20-36 12 V 3.0 Ω Figure 20-39 26. Find the equivalent resistance of the circuit shown in Figure 20-37 (See Sample Problem 20C.) 7.0Ω 7.0 Ω 12.0 V 7.0 Ω 1.5Ω 7.0 Ω R5 27. Two identical parallel-wired strings of 25 bulbs are Figure 20-37 connected to each other in series. If the equivalent resistance of the combination is 150.0 Ω when it is connected across a potential difference of 120.0 V what is the resistance of each individual bulb? (See Sample Problem 20C.) 28. For the circuit shown in Figure 20-38, determine the following: a. the current in the 2.0 Ω resistor , the potential difference across the 2.0 Ω resistor c. the potential difference across the 12.02 resistor d. the current in the 12.0 Ω resistor (See Sample Problem 20D.) 6.0 Ω 3.0 Ω 6.0 Ω 3.0 Ω 12.bs2-wrーコ 18.0 V 756 Chapter 20

Answer 1

26] R2 and R3 are in series and so their sum will be:

R = 7 + 7 = 14 ohms

this is parallel to a 7 ohm resistor

so, their equivalent resistance will be:

R' = [1/14 + 1/7]^-1 = 4.667 ohms

this is now in series with one 7 ohm resistor and another 1.5 ohm resistor. So, the equivalent resistance of the circuit is:

R_eq = 4.667 + 1.5 + 7 = 13.167 ohms.