Dear admin, would you please check again the answer of Homework > MCQ > Q6 (Graph of P vs R)? Thank you!

The question is asking about the resistivity of the wire (the greek letter rho). Perhaps you thought it was P for power?  As the temperature of a metal increases, its atoms vibrate more and provide more of a resistance to current flow.  So resistivity increases linearly, choice b.  Please see slides 16 and 17 of the notebook presentation for the explanation.  Thanks, John

The question is asking about the resistivity of the wire (the greek letter rho). Perhaps you thought it was P for power?  As the temperature of a metal increases, its atoms vibrate more and provide more of a resistance to current flow.  So resistivity increases linearly, choice b.  Please see slides 16 and 17 of the notebook presentation for the explanation.  Thanks, John

Dear John and Melissa, thank you for your reply.  I am sorry that I point the wrong question.  The question that I want to ask is Q18 (Graph of P vs R).  So sorry for this huge mistake.

The answer has no problem for Q18.  Thank you so much for your help!

I think we're ok with the answer. Answer (D) has a graph of P versus R.  For P = V^2/R.  Since V is constant, P is a function of 1/R. Graph (D) shows a 1/R function - large as R approaches zero, and approaching zero as R increases.  Does this help?