Conceptual Physics

positive number.)

V

3.7 A specialized 8.4-volt battery will supply 430 C of charge over its lifetime. Assume that the potential difference it can maintain
between its terminals does not change as it ages. It is wired into a simple circuit with a 350 ohm resistor. What is the resulting
lifetime of the battery?
s

Section 5 - Series wiring

5.1 Many flashlights are powered by a stack of batteries that are slid into the end of the flashlight one after another. Suppose you

have a flashlight that takes four ideal 1.5 V batteries. If the resistance of the bulb is 11 ohms, what is the current through the

bulb when the flashlight is turned on? The fact that the batteries are stacked end to end means they are wired in series.

A

Section 6 - Resistors in series

6.1 A portable electric heater is powered by a 45 V battery. It has four identical heating elements inside, wired in series. If a

current of 11 A runs through them when the heater is turned on, what is the resistance of each heating element?

ȍ

6.2 A 12 ohm, 14 ohm and 16 ohm resistor are connected in series. What is the equivalent resistance?

ȍ

6.3 Three hundred 14 ohm resistors are connected in series (think of a chain of cheap, old-fashioned holiday lights). What is the
equivalent resistance?

ȍ

6.4 There are six identical resistors in series. A multimeter measures the total potential difference across all the resistors as

331 V. 4.56 A of current flows through the resistors. (a) What is the equivalent resistance of this group of resistors? (b) What

is the resistance of each resistor?

(a) ȍ

(b) ȍ

6.5 The total potential difference across two resistors in series is 34.0 V. The current through them is 6.50 A. One resistor's

resistance is 2.00 ȍ. What is the other resistor's resistance?

ȍ

6.6 A 55 ȍ and 65 ȍ resistor are wired in series in a circuit that contains a 12 V battery. (a) What is the equivalent resistance of

the two resistors? (b) How much current is flowing in the circuit?

(a) ȍ

(b) A

6.7 The ammeter in the diagram displays 1.6 A

when the switch is open. What will it display

when the switch is closed?

A

6.8 A circuit contains a single resistor of 12.0 ohms and an ideal emf source (one with zero internal resistance). The current is
5.50 A. A second resistor is added in series, and the current falls to 4.23 A. What is the resistance of the second resistor?

ȍ

6.9 A 15.0 ȍ and 25.0 ȍ resistor are in series with a battery. The potential difference across the 15.0 ohm resistor is 4.50 V.

What is the potential difference across the battery?

V

6.10 Three silver wires of equal length are connected in series with a 1.50 V battery. Their cross-sectional areas are 1.00, 5.00

and 10.0 cm^2. (a) What is the potential difference across the narrowest wire? (b) The medium wire? (c) The widest wire?

Copyright 2007 Kinetic Books Co. Chapter 27 Problems^501