The heater element of a 120 V toaster is a 5.4 m length of nichrome wire,whose diameter is 0.48 mm.The resistivity of nichrome at the operating temperature of the toaster is 1.3 × 10^-6 Ω·m.The toaster is operated at a voltage of 120 V.The power drawn by the toaster is closest to:

Question

Quizplus · Accepted Answer

The power drawn by the toaster is given by the formula P = V^2 / R, where V is the voltage and R is the resistance. The resistance of the wire is given by the formula R = ρL / A, where ρ is the resistivity, L is the length, and A is the cross-sectional area. The cross-sectional area of the wire is given by the formula A = πd^2 / 4, where d is the diameter. Substituting these formulas into the first formula, we get P = V^2ρL / (πd^2 / 4). Plugging in the given values, we get P = (120 V)^2(1.3 × 10^-6 Ω·m)(5.4 m) / (π(0.48 mm)^2 / 4) ≈ 370 W.

The Heater Element of a 120 V Toaster Is a 5.4