Question

two wires of equal length are first connected in series and then in parallel with a voltage source.the ratio of heat developed in this two cases will be?
a.1:2 ,b.2:1 , c.4:1 ,d.1:4

Answer 1

proportional to the resistance R.


Let RS be the equivalent resistances of the wires if connected in series and RP  be the equivalent resistances of the wires if connected in parallel

Then RS =R+R=2R

And 1/ RP = 1/R +1/R

       1/ RP = 2/R

Or        RP =R/2

Now the ratio of heat produced is given by 

 

      = 1/4