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प्रश्न
Find the capacity of a capacitor which when put in series with a 10Ω resistor makes the power factor equal to 0.5. Assume an 80V-100Hz AC supply.
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उत्तर
Here, C=?, R = 10Ω, cosϕ = 0.5,
Ev = 80V, v = 100Hz
As cosϕ = `"R"/"Z"`, Z = `"R"/cosϕ=10/0.5` = 20
As R2 + `"X"_"C"^2="Z"^2`
∴ XC = `sqrt("Z"^2-"R"^2)=sqrt(20^2-10^2)=10sqrt3`
`1/(ω"C")=10sqrt3`,
C = `1/(ω10sqrt3)=1/(2πxx100xx10sqrt3)`
= 9.2 × 10−5 F
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