Question

A wire connected to a power supply of 230V has power dissipation p1.suppose the wire is cut into two equal pieces and connected parallel to the same power Supply.In this case power dissipiation is p2.the ratio p1/p2

Answer 1

Answer:

P1/P2 =1/4

Explanation:

Let the Resistance of the wire in the first case = R

Power = $\frac{V^2}{R}$

So, P1 =  $\frac{V^2}{R}$

Now, The wire is cut into two equal pieces.

Let the resistance of each piece = R'

R' = R/2  (Since R∝ 1/L)

The 2 pieces are connected in parallel, so

Req = R/4

So, P2 =  $\frac{4V^2}{R}$

So, P1/P2 =1/4

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