How many electrons per second pass through a section of wire carrying a current of `0.7A`?

Explanation

To solve the problem of how many electrons per second pass through a section of wire carrying a current of 0.7 A, we can follow these steps:

### Step 1: Understand the relationship between current, charge, and time
The current (I) in a conductor is defined as the rate of flow of charge (Q) through a cross-section of the conductor over time (T). Mathematically, this is expressed as:
\[ I = \frac{Q}{T} \]

### Step 2: Relate charge to the number of electrons
The total charge (Q) can also be expressed in terms of the number of electrons (n) and the charge of a single electron (e):
\[ Q = n \cdot e \]
where:
- \( e \) (the charge of an electron) is approximately \( 1.6 \times 10^{-19} \) coulombs.

### Step 3: Substitute the expression for charge into the current formula
Substituting \( Q \) in the current formula gives:
\[ I = \frac{n \cdot e}{T} \]

### Step 4: Rearrange the equation to find the number of electrons per second
To find the number of electrons passing through per second (which is \( \frac{n}{T} \)), we can rearrange the equation:
\[ \frac{n}{T} = \frac{I}{e} \]

### Step 5: Substitute the known values
Now we can substitute the values we know:
- Current \( I = 0.7 \) A
- Charge of an electron \( e = 1.6 \times 10^{-19} \) C

So, we have:
\[ \frac{n}{T} = \frac{0.7}{1.6 \times 10^{-19}} \]

### Step 6: Calculate the number of electrons per second
Now we perform the calculation:
\[ \frac{n}{T} = \frac{0.7}{1.6 \times 10^{-19}} \approx 4.375 \times 10^{18} \]

### Step 7: Present the answer in a suitable format
We can express this as:
\[ \frac{n}{T} \approx 4.375 \times 10^{18} \text{ electrons per second} \]

### Final Answer
Approximately \( 4.375 \times 10^{18} \) electrons pass through the wire per second.

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