Resistors with resistances of 8 ohms and 12 ohms, connected in parallel, are connected to a current source with
Resistors with resistances of 8 ohms and 12 ohms, connected in parallel, are connected to a current source with an EMF of 12 V and an internal resistance of 1.2 ohms. How much power is dissipated in the high resistance resistor?
R1 = 8 ohms.
R2 = 12 ohms.
r = 1.2 ohms.
EMF = 12 V.
N2 -?
The current power N2 is determined by the formula: N2 = U22 / R2, where U2 is the voltage at the ends of the second resistor, R2 is the resistance of the resistor.
We express the current strength in the entire circuit I by Ohm’s law for a closed loop: I = EMF / (R + r).
R = R1 * R2 / (R1 + R2).
R = 8 ohms * 12 ohms / (8 ohms + 12 ohms) = 4.8 ohms.
I = 12V / (4.8 Ohm + 1.2 Ohm) = 2 A.
U = U1 = U2.
U = I * R.
U = 2 A * 4.8 Ohm = 9.6 V.
N2 = (9.6V) 2 / 12Ω = 7.68W.
Answer: more resistance has a power of N2 = (9.6 V) 2/12 Ohm = 7.68 W.