Question

A 3.6-volt battery is used to operate a cell phone
for 5.0 minutes. If the cell phone dissipates
0.064 watt of power during its operation, the
current that passes through the phone is
(1) 0.018 A (3) 19 A
(2) 5.3 A (4) 56 A

Answer 1

The equation with the values for this one is P = VI, and we know some of the values, so substituting them in:

0.064 = 3.6 x I
I=0.064/3.6
=0.0177 = 0.018A

Answer 2

Explanation :

It is given that,

Potential energy, $V=3.6\ V$

Power dissipated,  $P=0.064\ Watt$

We know that the power dissipated is given by :

$P=VI$

I is the current passing through the phone.

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

$I=\dfrac{0.064\ W}{3.6\ V}$

$I=0.017\ A$

or

I = 0.018 A

Hence, the current that passes through the phone is (1) 0.018 A.