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Find the unknown quantities

Find the unknown quantities-example-1
User Unwise Guy
by
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1 Answer

12 votes

Answer:

I = 11/2 = 5.5

R = 60/11 ≈ 5.5Ω

Step-by-step explanation:

You use V = I·R twice.

Entire circuit: 140 = I·(20+R)

Resistor: 30 = I·R

Solving this system of equations gives:

140 = I·(20+R) = 20I + IR

30 = I·R

140 = 20I + 30

20I = 110

I = 11/2 = 5.5

R = 60/11 ≈ 5.5Ω

User Kiril Aleksandrov
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3.3k points