Saved Bookmarks
| 1. |
Q.7 A wire of length Land 3 identical cells of negligible internal resistance are connected in series. Due to the current, the temperature of the wire is raised by AT in a time t. A number N of similar cells is now connected in series with a wire of the same material and cross section but of length 2L. The temperature of the wire is raised by the same amount AT in the time. The value of N is |
|
Answer» ong>Answer: step by step Explanation: Here a wire of LENGTH L and three IDENTICAL cells of negligible internal resistances are connected in series. Let, the terminal potential difference of each cell is V and resistance of wire is R. then heat developed in the wire in time t is H=( R (3V) 2
)=msΔT where m is the mass of wire s is the specific heat of its MATERIAL and ΔT is rise in its temperature When N such identical cells are connected in series the effective terminal potential is NV volts and if the length of wire is DOUBLED its resistance and mass also doubled then heat developed in the wire is H=( 2R (NV) 2
)t=2msΔT dividing both equations we get 2×9 N 2
=2 ∴N=6 May be helpful for youMark as brainlest pls.... |
|