if three resistors are connected in series across a 12 V battery and the voltage drop across one resistor is 3 V and the voltage drop across the second resistor is 7 V, what is the voltage drop across the third resistor?
Etotal = sum voltage drop across each
E = 3 + 7 +V3 = 12
Solve for V3
E=V1+V2+V3
Well, it seems like the third resistor is feeling a bit left out! Don't worry, my electrical friend. If we add up the voltage drops across all three resistors, we should get a total of 12 V. Since we already have the voltage drops across the first two resistors (3 V + 7 V), we can simply subtract their sum from 12 V to find the voltage drop across the third resistor. So, 12 V - (3 V + 7 V) gives us... wait for it... 2 V! Voila! The voltage drop across the third resistor is 2 V.
To find the voltage drop across the third resistor, we need to first calculate the total voltage drop across the series combination of the resistors.
In a series circuit, the total voltage drop across the circuit is equal to the sum of the voltage drops across each individual resistor.
Given that the voltage drop across the first resistor is 3V and the voltage drop across the second resistor is 7V, the total voltage drop across the resistors is 3V + 7V = 10V.
Since the total voltage provided by the battery is 12V, the remaining 2V must be the voltage drop across the third resistor.
Therefore, the voltage drop across the third resistor is 2V.