Question

# Two conducting wires of the same material and of equal lengths and equal diameters are first connected in series and then in parallel in a circuit across the same potential difference. The ratio of heat produced in series and parallel combinations would be :

A
1:2
B
2:1
C
1:4
D
4:1

Solution

## The correct option is D 1:4Since the two wires have same material, length and diameter, they have the same resistance. Let the resistance of each wire be R.Let applied potential difference be $$V$$.$$R_{series}=R_1+R_2$$             $$=R+R=2R$$$$P_{series} = V^2 / R_{series}$$             $$=V^2/(2R)\quad ..........(i)$$$$\cfrac{1}{R_{parallel}} = \cfrac{1}{R_1}+\cfrac{1}{R_2}$$$$R_{parallel}=R/2$$$$P_{parallel} = V^2 / R_{parallel}$$              $$=2V^2/R\quad ............(ii)$$Dividing (ii) from (i),$$\dfrac{P_{series}}{P_{parallel}} = 1/4$$ScienceNCERTStandard X

Suggest Corrections

0

Similar questions
View More

Same exercise questions
View More

People also searched for
View More