00:01Hi friends, never stop learning, never stop developing.
00:07An electrical circuit consists of three resistors connected in series.
00:13Now, we're asked to calculate the voltage across each resistor.
00:21Before answering this question, consider the following short animation.
00:27In a series circuit, each resistor carries the same current.
00:32This is because no current accumulates across each resistor.
00:37This is a simple, well-known concept.
00:43To measure voltage, we can use a voltmeter.
00:50It turns out that each voltmeter's reading is different.
00:55How do we calculate the voltage value?
01:01Simple.
01:03Previously, we learned about Kirchhoff's voltage law.
01:08This circuit consists of only a loop.
01:12Assume the loop rotates counterclockwise.
01:18The algebraic sum of the voltages in a closed circuit is zero.
01:25There are four electrical components.
01:29For a battery, the arrow of the loop touches the positive terminal of the voltage source first, so the battery
01:35voltage is negative.
01:39For a resistor, all current through the resistor is in the opposite direction to the loop.
01:44So, the voltage across each resistor is positive.
01:49Minus epsilon plus IR1, plus IR2, plus IR3 equals zero.
01:57We can add up each factor containing the electric current.
02:02From here, we can find the electric current.
02:09Now we will calculate the voltage across each resistor.
02:15According to Ohm's law, voltage is the product of the resistance value and the electric current through it.
02:23The electric current across each resistor is the same.
02:30I don't recommend memizing this formula.
02:33As long as we understand Ohm's law and Kirchhoff's laws, this equation can be obtained immediately.
02:42The values of the voltage source and the resistance are listed on the problem sheet.
02:48If I'm not mistaken, V1 is 2 volts.
02:54V2 is 4 volts.
02:59And V3 is 6 volts.
03:03The sum of these voltages is 12 volts, corresponding to their voltage source.
03:10Because the voltage from their voltage source is divided across several resistors, this circuit is known as a voltage divider
03:17circuit.
03:19Happy learning, everyone!
03:21Happy learning, everyone!
03:21Happy learning, everyone!
03:22Happy learning, everyone!
03:23Happy learning, everyone!
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