Question

two conductingwires of the same material and of equal length and equal diameter are first connected in series and then parallel in circuit across the sane potential difference the ratio of heat produced in series and parallel combination would be​

Answer 1

Let resistance of each wire is R Ω.  if two wires are connected in series, then its equivalent resistance is 2R Ω .

 

If two wires are connected in parallel, then its equivalent resistance is R/2 Ω .

 

Let Current drawn by series combination = V/2R  = i Amps.

Current drawn by parallel combination = V / (R/2)  = 4i Amps

 

Heat produced in series combination = i2 2R = (2i2 R) Watts   ......................(1)

 

Heat produced in parallel combination = 16i2 (R/2)  = ( 8i2 R) Watts   ......................(2)

 

From eqn.(1) and (2), we get ratio of heat produced in series combination to heat produced in parallel combination = 1 :4