00:02Hello friends, be grateful that you can still open your eyes this morning, because you have
00:07the opportunity to learn something new.
00:11An electric circuit consists of two batteries and two resistors.
00:17Now, we are asked to calculate the electric current flowing through the electric circuit.
00:25To be clearer, this is a larger view of the electric circuit.
00:32A more accurate method is to install all the components exactly as shown in the picture,
00:37then measure the electric current using an ammeter.
00:42The number displayed on the outside of the ammeter is the electric current value.
00:49If we don't have the resources for that, there's one concept worth trying, Kirchhoff's voltage
00:54lore.
00:57The algebraic sum of the voltages in a closed circuit is equal to zero.
01:09Mathematically, sigma v in a closed circuit is zero.
01:16In the language of Kirchhoff's laws, this circuit consists of a closed circuit, or one loop.
01:23In addition to considering the direction of the electric current, we must also consider
01:27the direction of the loop.
01:31Assume the loop is counterclockwise, and the current is clockwise.
01:40Sometimes the loop aligns with the current, sometimes it doesn't.
01:46This means there's a sign on the voltage label.
01:51When the loop touches the negative terminal of the battery, the voltage is positive.
01:59The voltage on a two-volt battery is positive.
02:03The voltage on a four-volt battery is negative.
02:10For resistors, when the loop aligns opposite the reference current, the resistor voltage
02:14is positive.
02:18The voltage across an eight-ohm resistor is positive.
02:24The voltage across a twelve-ohm resistor is also positive.
02:29Overall, two minus four, plus eight I, plus twelve I equals zero.
02:37This algebraic calculation is quite simple, twenty I equals two, or, I equals zero point two amps.
02:47The sign of the current is positive, meaning that a current of zero point two amps will flow
02:52through the circuit counterclockwise.
02:58Happy learning everyone!
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