A string of 25 identical Christmas tree lights are connected in series to a 120 V source. The string dissipates 64 W. What is the equivalent resistance of the light string? Answer in units of Ω.
What is the resistance of a single light? Answer in units of Ω.
What power is dissipated in a single light? Answer in units of W.
One of the bulbs burns out. The lamp has a wire that shorts out the bulb filament when it burns out, dropping the resistance of the bulb to zero. What is the resistance Rnew of the light string now Answer in units of Ω
Find the power Pnew dissipated by the string now. Answer in units of W.
What is the resistance of a single light? Answer in units of Ω.
What power is dissipated in a single light? Answer in units of W.
One of the bulbs burns out. The lamp has a wire that shorts out the bulb filament when it burns out, dropping the resistance of the bulb to zero. What is the resistance Rnew of the light string now Answer in units of Ω
Find the power Pnew dissipated by the string now. Answer in units of W.
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W= IE . W = I x I x R. W = E x E/R. 64 = 120 x 120 / R.
R = 120 x 120 / 64 = 225 Ohms.
225/ 25 = 9 Ohms. W = 9 x 9/9 = 9 Watts
R = 120 x 120 / 64 = 225 Ohms.
225/ 25 = 9 Ohms. W = 9 x 9/9 = 9 Watts