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A wire connected to a power supply of 23...

A wire connected to a power supply of 230V has power dissipation `P_(1)`. Suppose the wire is cut into two equal pieces and connected parallel to the same power supply. In this case power dissipation is `P_(2)`. The ration `(P_(2))/(P_(1))` is.

A

`1`

B

`2`

C

`3`

D

`4`

Text Solution

Verified by Experts

The correct Answer is:
D
`V =230 V `
`P = V^2/R_1`
`:." "P prop 1/R` Since V is same
`1/R_2 = 1/(R_2/2) + 1/(R_1/2) = 2/R_1 + 2/R_1`
`1/R_2 = (2+2)/R_1 = 4/R_1`
`:."R"_2 = R_1/4` `:." "R_1 = 4R_2`
`P_1/P_2 = R_2/R_1`
`:." "P_2/P_1 = R_1/R_2 = (4R_2)/R_2 = 4`
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