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Explain the construction and working of transformer. |
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Answer» Solution :Venturimeter : This device is USED to measure the rate of flow (or say flow speed) of the incompressible fluid flowing through a pipe. It works on the principle of Bernoulli.s theorem . It consists of two WIDER tubes A and A. (with cross sectional area A) CONNECTED by a narrow between the wide the narrow tubes. The manometer contains a LIQUID of density `.rho_m.`. Let `P_1` be the pressure of the fluid at the wider region of the tube A. Let us assume that the fluid of density `.rho.` flows from the pipe with speed `.v_1.` and into the narrow region, its speed increases to `.v_2.` . According to the Bernoulli.s equation, this increase in speed is accompanied by a decrease in the fluid pressure `P_2` at the narrow region of the tube B. Therefore, the pressure difference between the tube A and B is noted by measuring the height difference `(DeltaP = P_1 - P_2)` between the surfaces of the manometer liquid. From the equation of continuity, we can say that `Av_1 = av_2` which means that `v_2 = A/a v_1` Using Bernoulli.s equation , `P_1 + rho (v_1^2)/(2) = P_2 + rho (v_2^2)/(2) = P_(2) + rho 1/2 (A/a v_1)^(2)` From the above equation, the pressure difference `DeltaP = P_1 - P_2 = rho (v_1^2)/(2) ((A^2 - a^2))/(a^2)` Thus, the speed of flow of fluid at the wide end of the tube A `v_1^2 = (2 (DeltaP)a^2)/(rho (A^2 - a^2)) implies v_1 = sqrt((2 (Delta P)a^2)/(rho(A^2 - a^2)))` The volume of the liquid flowing out per second is `V = A v_1 = A sqrt((2(DeltaP)a^2)/(rho(A^2 - a^2))) = aA sqrt((2(DeltaP))/(rho(A^2 - a^2)))`. |
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