A 90 W electric blanket runs at 12 V?

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