Question

Find the power dissipated in each of these extension cords:

(a) an extension cord having a 0.0600-Ω resistance and through which 5.00 A is flowing;

a) 1.50 W
b) 0.75 W
c) 15.0 W
d) 3.75 W

Answer 1

The power dissipated in the extension cord with a resistance of 0.0600 ohms and 5.00 A current is 1.50 W. For the cheaper cord with a resistance of 0.300 ohms, the power dissipation is 7.50 W.

Step-by-step explanation:

Power Dissipation in Extension Cords

To find the power dissipated in an extension cord, we can use the formula derived from Joule's law: Power (P) = Current (I) squared times Resistance (R), or P = I²R. For a cord with a resistance of 0.0600 ohms through which 5.00 A is flowing, we calculate as follows:

P = I²R
= (5.00 A)²(0.0600 Ω)
= 25 A²(0.0600 Ω)
= 1.50 W

For the cheaper cord with a resistance of 0.300 ohms, the power dissipation is calculated like this:

P = I²R
= (5.00 A)²(0.300 Ω)
= 25 A²(0.300 Ω)
= 7.50 W

Therefore, the power dissipated in the first cord is 1.50 W, and for the cheaper cord with thinner wire and higher resistance, the power dissipation is significantly higher at 7.50 W.