A wire when connected to 220 V mains supply has power dissipation P_{1}. Now the wire is cut into two equal pieces which are connected in parallel to the same supply. Power dissipation in this case is P_{2}. Then P_{2}:P_{1} is

- 1
- 2
- 3
- 4

**Answer**

P = V^{2}/R and R = ρl/A

Let P_{1} = V^{2}/R

When the wire is cut down into two pieces, then each wire would have length of l/2 and resistance of R/2.

Equivalent resistance of wire connected in parallel, R_{2} = R/4 (each wire has resistance R/2)

P_{2} = V^{2}/R_{2} = 4P_{1}

**The correct option is D.**