Understanding Current Sense in Circuits: The Reversal Dilemma

  • Thread starter Thread starter sevag00
  • Start date Start date
  • Tags Tags
    Current
AI Thread Summary
The discussion centers on the confusion regarding the direction of current flow in a circuit problem involving an 11Ω resistor with a current ib of -2A. The solutions manual reverses the current direction to left to right and uses a value of 2A, leading to questions about the necessity of this reversal. It is clarified that the negative sign indicates the current flows in the reverse direction, meaning it can indeed be solved from either direction. The key takeaway is to adhere to the sign convention when analyzing current flow. Understanding these principles allows for flexibility in solving circuit problems.
sevag00
Messages
80
Reaction score
1
Hi. It's me again with another confusing circuit problem. The first attached image below shows ib going from right to left through the 11Ω resistor and ib is given -2A. In the solutions manual of the book, it has reversed the direction of the current as in going from left to right and taken the value 2A.
My questions is, why has the solutions manual reversed the direction and not just solved it from left to right and taking the current -2A? Could it be solved it both ways?
 

Attachments

  • Capture.JPG
    Capture.JPG
    6.8 KB · Views: 429
  • Capture2.JPG
    Capture2.JPG
    8.3 KB · Views: 419
Physics news on Phys.org
The current always flows from +ve terminal to -ve. The negetive sign just indicates that current is positive in the reverse direction (in other words it is flowing in the reverse direction). Since ib is given as -2A it is saying that the current is 2A in the reverse direction (which is indicated in the solution manual). It could be solved in both ways. Just keep in mind the sign convention.
Regards
 
Aha. Thanks for the answer.
 
Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .
TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
Back
Top