Question

For the following series circuit, compute the power in R1, R2, and R3 if the circuit values are E = 24 volts, R1 = 8, R2= 12, and R3 = 28. Power in R1 = watts Power in R2 = watts Power in R3 = watts Compute the total power delivered to the circuit by the 24-volt battery: watts

Answer 1

Step-by-step explanation:

You add resistances to get the total R in a series circuit.

R = R1 + R2 + R3

R = 8 + 12 + 28

R = 48 ohms.

Next the current is the same going through each of the resistors.

I = E / R

I = 24 / 48

I = 1/2

I = 0.5

But you are asked for power in each resistor

P = I * I*R

P = I^2 * R1

P1 = (0.5^2) * 8

P1 = 1/4 * 8 = 2 watts

P2 = I^2 * R2

P2 = (1/2)^2 * 12

P2 = 3 watts

P3 = 1/4 * 28

P3 = 7 watts.

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The total power can be found two ways: either by just adding what you got or using voltage.

P = E * I

P = 24 * 1/2 = 12 watts.

Now we can try it the other way.

P = P1 + P2 + P3

P = 2 + 3 + 7

P = 12 watts

Both answers agree.

Answer 2

Power in R1 = 2 watts

Power in R2 = 3 watts

Power in R3 = 7 watts

Compute the total power delivered to the circuit by the 24-volt battery: 12 watts