A 15 V constant voltage battery is connected to 120 kΩ resistor. A 15 V constant voltage battery is connected to 120 kΩ resistor. 1) What is the current in the resistor in [mA]?Multiple Choice question2) How many electrons pass through the resistor each second?a) 7.8x1014 electronsb) 1.25x10-4 electronsc) 1.6x10-19 electrons

Respuesta :

We will have the following:

1)

[tex]I=\frac{V}{R}\Rightarrow I=\frac{15V}{120000\Omega}\Rightarrow I=1.25\cdot10^{-4}A[/tex][tex]\Rightarrow I=0.125mA[/tex]

2)

First we determine the quantity of coulombs:

[tex]Q=(1.25\cdot10^{-4}A)(1s)\Rightarrow Q=1.25\cdot10^{-4}C[/tex]

Now, we know that 1 coulomb represents 6.24*10^18 electrons, so:

[tex]1.25\cdot10^{-4}C\cdot\frac{6.24\cdot10^{18}\text{electrons}}{1C}=7.8\cdot10^{14}\text{electrons}[/tex]

So, approximately 7.8*10^14 electrons pass each second.