How much power is dissipated in the power cord?

Question

Your toaster has a power cord with a resistance of 0.019 connected in series with a 11.3 nichrome heating element. The potential difference between the terminals of the toaster is 120 V.

(a) How much power is dissipated in the power cord?

__________W

(b) How much power is dissipated in the heating element?

__________kW

Answer 1

If 11.3 nichrome heating element, means a 11.3 ohm nichrome heating element, then:

pwr cord = 0.019 ohms

heating element = 11.3 ohms

Series resistance = 11.3 + 0.019 = 11.32 ohms

Voltage = 120V

I = Current in series circuit  = V/R = 120 / 11.32

= 10.60 amps

(a) watts dissipated in cord?

P = I^2 * R = 10.60^2 amps * 0.019 ohms = 2.13 Watts

(b) watts dissipated in heating element?

P = I^2 * R = 10.60^2 amps * 11.3 ohms = 1269.67 Watts

Answer 2

Add the 2 resistances together to get the total amperage drawn by everything. Then, using that figure, square the amperage times the resistance of each item. That will give you the answers that you seek. You need to do this yourself since doing so is in your own best interest. This is not hard, and if you are in any kind of engineering study, this is simple stuff.

The applied voltage, as given is divided by the total resistance of the line cord and the appliance. That gives you the total amperage draw. Use that figure and follow the directions already given. Because the circuit in question is a series circuit, the current in all parts of the circuit is going to be the same, so squaring the current, and multiplying that by the resistance will work out, as previously stated.