Chapter 4: Q42E (page 843)

The battery for a certain cell phone is rated at $3.70 V$ .According to the manufacturer it can produce $3.15 \times 10^{4} J$ of electrical energy, enough for $2.25 h$ of operation, before needing to be recharged. Find the average current that this cell phone draws when turned on.

Short Answer

Expert verified

The average current cell phone draws when turn on is $0.45 A$ .

Step by step solution

Concept/Significance of average current.

Time-averaged current is the total amount of charge passing through a conductor in a time interval.

$I_{avg} = \frac{∆ q}{∆ t}$

Determination of the average current that this cell phone draws when turned on

The average power of the battery is given by,

$P = \frac{E}{t}$

Here, E is the electric energy and t is the time

Substitute all the values in the above equation.

$P = \frac{3.15 \times 10^{4} J}{5.25 h (3600 s / h)} = 1.66 W$

The average current is given by,

$I = \frac{P}{V}$

Here, P is the Power and V is the battery of the phone.

Substitute all the values in the above,

$I = \frac{1.66 W}{3.70 V} = 0.45 A$

Thus, the average current cell phone draws when turn on is $0.45 A$ .

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The battery for a certain cell phone is rated at $3.70 V$ .According to the manufacturer it can produce $3.15 \times 10^{4} J$ of electrical energy, enough for $2.25 h$ of operation, before needing to be recharged. Find the average current that this cell phone draws when turned on.

Short Answer

Step by step solution

Concept/Significance of average current.

Determination of the average current that this cell phone draws when turned on

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The battery for a certain cell phone is rated at3.70V.According to the manufacturer it can produce3.15×104Jof electrical energy, enough for 2.25hof operation, before needing to be recharged. Find the average current that this cell phone draws when turned on.

Short Answer

Step by step solution

Concept/Significance of average current.

Determination of the average current that this cell phone draws when turned on

One App. One Place for Learning.

Most popular questions from this chapter

Recommended explanations on Physics Textbooks

Physics of Motion

Energy Physics

Modern Physics

Waves Physics

Physical Quantities And Units

Mechanics and Materials

Study anywhere. Anytime. Across all devices.

The battery for a certain cell phone is rated at $3.70 V$ .According to the manufacturer it can produce $3.15 \times 10^{4} J$ of electrical energy, enough for $2.25 h$ of operation, before needing to be recharged. Find the average current that this cell phone draws when turned on.