Saved Bookmarks
| 1. |
In order to heat a liquid an electric heating coil is connected is to a cell of emf E = 12 V and internal resistance r = 1 Omega. There are three options for selecting the resistance (R) of the heating coil. R can be chosen as 1 Omega, 2 Omega or 4 Omega. The cell has a rating of 2000 mAh (milli Ampere hour) and it is to be used to heat the liquid till it expires. [The cell maintains constant emf till it lasts] (a) Which value of R will you chose so that maximum heat (H_0) is transferred to the liquid before the cell expires? Calculate H_(0). (b) Which value of R will chose so that heat is transferred to the liquid at fastest possible rate? What percentage of H_(0) (as obtained in (a)) is transferred to the liquid in this case by the time the cell expires ? |
|
Answer» (B) `1 Omega,62.5 %` |
|