How to Calculate the Number of Electrons Passing Through a Device

Question:

What is the method to determine the number of electrons passing through a device based on the current supplied by a battery and time?

Answer:

The number of electrons passing through a device can be calculated by understanding the relationship between current, charge, and time. Let's break it down step by step:

Understanding the Concept:

When a battery supplies a current to a portable device, the amount of charge passing through the device can be calculated using the formula: Q = I * t. Where Q is the charge, I is the current, and t is the time.

Given Data:

Current (I): 0.149 A

Time: 12 hours

Calculating Total Charge:

First, we need to convert the time from hours to seconds. 12 hours = 12 hours * 60 minutes/hour * 60 seconds/minute = 43,200 seconds.

Now, using the formula Q = I * t, we find the total charge: Q = 0.149 A * 43,200 s = 6436.8 C.

Determining Number of Electrons:

Since one electron has a charge of 1.6 x 10^(-19) C, we can calculate the total number of electrons passing through the device: 6436.8 C / (1.6 x 10^(-19) C) = 4.02 x 10^22 electrons. Therefore, approximately 4.02 x 10^22 electrons pass through the device in twelve hours.