Please find the power dissipated by the resistor 2, P2, in the circuit.
Vtot = 12V
R1 = 20Ω
R2 = 30Ω
R3 = 15Ω
Ohm's Law:
V = IR
I = V/R
R = V/I
Watt's Law:
In a series circuit,
P = IV
P = V^2/R
P = I^2R
Rtotal = R1 + R2 + R3 + ... + Rn
Rtotal = R1 + R2 + R3 + R4