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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

  • Option 1)

    1

  • Option 2)

    4

  • Option 3)

    2

  • Option 4)

    3

 

Answers (1)

best_answer

As we have learned

Power dissipiated in the external circuit -

(\frac{nE}{R+nr})^{2}\cdot R

-

 

 Initially P_1 = \frac{V^2 }{R}

R_{eq}= \frac{R}{4}

P_2 = \frac{V^2}{R/4}= 4\frac{V^2}{R}=4P_1

\therefore \frac{P_2}{P_1}= 4

 

 

 

 

 


Option 1)

1

Option 2)

4

Option 3)

2

Option 4)

3

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Plabita

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