A string of 14 identical Christmas tree lights are connected in series to a 124 V source. The string dissipates 70 W. What is the equivalent resistance of the light string? Answer in units of Ω.

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Physics

Nylah Meyers

26 September, 09:56

A string of 14 identical Christmas tree lights are connected in series to a 124 V source. The string dissipates 70 W. What is the equivalent resistance of the light string? Answer in units of Ω.

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Zoey Mckenzie · Answer 1

V=IR

P=VI=V^2/R

R (total) = 14R

70W = (124V) ^2/14R

R=124^2/14*70=15.7omhs per light

R (total) = 14R=219.6omhs=220ohms total equivalent resistance of the light string