Question

The battery for a certain cell phone is rated at 3.70 V. According to the manufacturer it can produce 3.00×10^4J of electrical energy, enough for 7.20 h of operation, before needing to be recharged. Find the average current that this cell phone draws when turned on.

Answer 1

Answer:

$I_{avg}=0.3135A$

Explanation:

Given data

Voltage V=3.70V

time t=7.20h=25920s

Energy E=3.00×10⁴J

To find

Average current I

Solution

As we know that power is:

$Power=\frac{Energy}{y\time} \\Power=\frac{3.00*10^{4}J }{25920s}\\ Power=1.16W\\Also\\Power=V_{voltage}*I_{avg}\\ 1.16W=3.70V*I_{avg}\\I_{avg}=1.16/3.70\\I_{avg}=0.3135A$