# Ch26Word - Chapter 26 p. 1 CHAPTER 26 DC Circuits 1. ( a )...

This preview shows pages 1–2. Sign up to view the full content.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Chapter 26 p. 1 CHAPTER 26 DC Circuits 1. ( a ) For the current in the single loop, we have I a = V /( R a + r ) = (8.50 V)/(68.0 + 0.900 ) = 0.123 A. For the terminal voltage of the battery, we have V a = I a r = 8.50 V (0.123 A)(0.900 ) = 8.39 V . ( b ) For the current in the single loop, we have I b = V /( R b + r ) = (8.50 V)/(680 + 0.900 ) = 0.0125 A. For the terminal voltage of the battery, we have V b = I b r = 8.50 V (0.0125 A)(0.900 ) = 8.49 V . 2. The voltage across the bulb is the terminal voltage of the four cells: V = IR bulb = 4( Ir ); (0.62 A)(12 ) = 4[2.0 V (0.62 A) r ], which gives r = 0.23 . 3. If we can ignore the resistance of the ammeter, for the single loop we have I = / r ; 25 A = (1.5 V)/ r , which gives r = 0.060 . 4. We find the internal resistance from V = Ir ; 9.8 V = [12.0 V (60 A) r ], which gives r = 0.037 . Because the terminal voltage is the voltage across the starter, we have V = IR ; 9.8 V = (60 A) R , which gives R = 0.16 . 5. When the bulbs are connected in series, the equivalent resistance is R series = ? R i = 4 R bulb = 4(90 ) = 360 . When the bulbs are connected in parallel, we find the equivalent resistance from 1/ R parallel = ?(1/ R i ) = 4/ R bulb = 4/(90 ), which gives R parallel = 23 . 6. ( a ) When the bulbs are connected in series, the equivalent resistance is R series = ? R i = 3 R 1 + 3 R 2 = 3(40 ) + 3(80 ) = 360 . ( b ) When the bulbs are connected in parallel, we find the equivalent resistance from 1/ R parallel = ?(1/ R i ) = (3/ R 1 ) + (3/ R 2 ) = [3/(40 )] + [3/(80 )], which gives R parallel = 8.9 . 7. If we use them as single resistors, we have R 1 = 25 ; R 2 = 70 . When the resistors are connected in series, the equivalent resistance is R series = ? R i = R 1 + R 2 = 25 + 70 = 95 . When the resistors are connected in parallel, we find the equivalent resistance from 1/ R parallel = ?(1/ R i ) = (1/ R 1 ) + (1/ R 2 ) = [1/(25 )] + [1/(70 )], which gives R parallel = 18 ....
View Full Document

## This homework help was uploaded on 04/21/2008 for the course PHYS 292 taught by Professor Buldum during the Spring '08 term at The University of Akron.

### Page1 / 29

Ch26Word - Chapter 26 p. 1 CHAPTER 26 DC Circuits 1. ( a )...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online