Power in Circuits Video Lessons

Concept

# Problem: How much power is dissipated by each resistor in the figure below, in which V = 9 V and R2 = 15 Ω?

###### FREE Expert Solution

In this problem, we are dealing with power in circuits. Thus, we'll need the relation:

Power in circuits:

$\overline{){\mathbf{P}}{\mathbf{=}}{\mathbf{V}}{\mathbf{i}}{\mathbf{=}}{{\mathbf{i}}}^{{\mathbf{2}}}{\mathbf{R}}{\mathbf{=}}\frac{{\mathbf{V}}^{\mathbf{2}}}{\mathbf{R}}}$

The potential across each resistor and the current in the circuit are unknown. Thus, we'll need more relations:

Ohm's law:

$\overline{){\mathbit{i}}{\mathbf{=}}\frac{\mathbf{V}}{\mathbf{R}}}$

Lastly, we need the circuit resistance. The given resistors are in series.

Equivalent resistance:

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###### Problem Details

How much power is dissipated by each resistor in the figure below, in which V = 9 V and R2 = 15 Ω?