I'm sure I am doing something wrong as I keep getting the wrong answer, but if someone could explain how to solve this question for me that would be great.
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\$\begingroup\$ Show us your work. \$\endgroup\$– G36Commented Mar 9, 2018 at 13:32
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1\$\begingroup\$ working out P=I^2*R P=(-0.0322)^2*47 P=0.049W (3 s.f) \$\endgroup\$– YinnyCommented Mar 9, 2018 at 13:36
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1\$\begingroup\$ Looks good P = 0.04873148W ≈ 0.049W. Who said that this is a wrong answer? \$\endgroup\$– G36Commented Mar 9, 2018 at 13:42
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\$\begingroup\$ The power isn't absorbed, but dessipated. And I don't see any wrong work here, as current flows through both resistors the same, while the resistance is different. My result is the same, P = 0.04783W \$\endgroup\$– JakeyCommented Mar 9, 2018 at 13:43
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\$\begingroup\$ The worksheet answers said it was wrong but I'll assume it's an error as you said it was correct. Thanks G36 and Jakey! \$\endgroup\$– YinnyCommented Mar 9, 2018 at 13:47
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1 Answer
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Convention is that positive current flows from plus to minus (higher to lower voltage.) Adjacent R's with opposite signed voltage drops suggests the diagram has an error. Either another branch should connect to the node between them, or some similarly crucial piece of information has been omitted.
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\$\begingroup\$ The order and directions are stupid but that's common in first year electronics - they want you to think hard about relative voltages and current flowing in different directions. The question makes sense if for example V1 is negative and V2 is positive (note that even the current is negative, flowing the opposite way in relation to the arrow) \$\endgroup\$– pipeCommented Aug 22, 2018 at 12:41