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A 80 V - 800 W heater is to be operated on a 100 V - 50 Hz a.c. supply. Calculate the inductance of the choke required. |
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Answer» Here, `V = 80 V, P = 800 W` current required, `I = (P)/(V) = (800)/(80) = 10 A`, `R = (V^(2))/(P) = (80 xx 80)/(800) = 8 Omega` For a.c. supply, `E_(v) = 100 V, I_(v) = I = 10 A`, `v = 50 hz` `:. Z = (E_(v))/(I_(v)) = (100)/(10) = 10 ohm` Now `R^(2) + X_(L)^(2) = Z^(2)` `:. X_(L) = sqrt(Z^(2) - R^(2)) = sqrt(10^(2) - 8^(2)) = 6 ohm` `X_(L) = omega L = 2 pi v L` `:. L = (X_(L))/(2 pi v) = (6)/(2 xx 3.14 xx 50) = 0.019 H` |
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