A series combination of two resistors of resistance 12 Ù and 8 Ù is connected across a source of emf 24 V. What is the potential difference across 8 Ù resistors?
Do you know the formula for this?
Yes, I know the formula. It is called Ohm's Law.
Why do you write "8 Ohm resistors" if there is only one of them?
That's my point, this is the exact question and i don't understand it. I didn't write 8 ohm resistors, my book did. Do you understand what they're asking?
thanks
There are four possible answers:
9.6V
14.4V
20V
24V
I=U/(R1+R2) =2.4/(12+8) =1.2 A,
U1= I•R1= 1.2•8 = 9.6 V,
U2= I •R2=1.2•12=14.4 V.
Yes, I can help you with this. For a series combination of resistors, the total resistance (R_total) is the sum of the individual resistances (R1 + R2 + ...), and the total voltage (V_total) is equal to the sum of the potential differences across each resistor.
In this case, the resistors have resistances of 12 Ù and 8 Ù, and the source has an electromotive force (emf) of 24 V. We need to find the potential difference across the 8 Ù resistor.
To find the potential difference across a resistor in a series circuit, we can use Ohm's Law, which states that V = I * R, where V is the potential difference (voltage), I is the current, and R is the resistance.
Since the resistors are in series, the current is the same for both resistors. Let's call this current I.
Now, we can use the equation V_total = I * R_total to find the current. In this case, V_total is 24 V and R_total is the sum of the resistances:
R_total = 12 Ù + 8 Ù = 20 Ù
So the equation becomes:
24 V = I * 20 Ù
To find the current I, we can rearrange the equation:
I = 24 V / 20 Ù = 1.2 A
Now that we know the current, we can calculate the potential difference across the 8 Ù resistor using Ohm's Law:
V_8Ù = I * R_8Ù = 1.2 A * 8 Ù = 9.6 V
Therefore, the potential difference across the 8 Ù resistor is 9.6 V.