What is the resistance of the wire in the blanket?
How much current does the wire carry?
2 Answers

Given,
Power (P) = 90 Watts
Voltage (V) = 12 volts
Resistance (R) =?
Current (I) =?
We know that:
Power (P) = V²/R
90 = (12)²/R
90 x R = (12)²
90 x R = 144
Resistance(R) = 144/90 = 1.6
∴ Resistance (R) = 1.6 Ω
Now,
V = IR
I = V/R = 12/1.6 = 7.5 A
∴ current (I) = 7.5 A

P=IV
I = V/R
P = V^2/R
R= V^2/P
R = 144/90
R = 1.6 Ohms
I = V/R
I = 12/1.6
I = 7.5