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rl CF —i i ey Pe [Ans: 600V, 16.66A, 83.33A, rote) a ~ ae. a nn 4 = = r a a a r i 4 | ; ‘nd ie QN.3 Draw the phasor diagr am for ide: ; Or ideal and rea} transformer for inductive and capacitive loads. - ON.4 A step up transformer supp]; | Be ae | pplies a current of eS load is 0.8 lagging. Given that R; =0.5 Ba Z the load at 200 V. The arr ae factor of the ’ a Ro i 450o0hmis and Xo = 25 one ohm, R =2 ohm, xX? =4 ohm, k _ 2, 0 ohms. Calculate : teva a ate the m “t reference phasor and Calculate the input power fatten Sunde and pase i Vi = 129.98.6.5° V, I, = 10.56,”-3 ; [Vi V, li = 10.56.2-37,88° A and input pf= 0.7] lagging] a3 QN.S What are the varj y E ‘aPlous Types of power lo i as Bc; yp ss€s In transformer? Derive the condition for maximum ON.6 A 230V/ 2300V single-pha ss | ase transformer is excited by 230V ac vy uivaler resistance and reactance referred to primary side are 0.1 i and 0.4 ohm reepectivel aa Given that Ro = 500 ohms and Xo = 200 ohms. The load impedance is (400 + 3600) ohm ‘% Calculate: a) Primary current b) Secondary terminal voltage c) Input power factor | om [li = 30 A V2 = 2075.4V, and input pf = 0.52 lagging] ON.7 Derive the Emf Equation E.>=4.44fN>@,, for emf induced in seconda ae 3 | ry winding of a transformer. Symbols have their usua! meanings. QN.8 A 2) KVA, 6600V/ 250V single phase transformer has the following parameters: ( Ri = § ohm, X; = 15 ohm, R2 = 0.02 ohm, X) = 0.05 ohm. ‘ i Calculate the full load voltage regulation at a power factor a) 0.8 lag b) unity c) 0.8 lead. ae [2.7 %, 1.3 % and -0.782 %] - QN.9 The flux in the transformer core remains practically constant from no load to full load. Justify the Statement. QN.I0 Define 'Voltage regulation’ and ‘efficiency’ of a transformer. i‘ ol a = wae ive oe. QN.1!1. What are the conditions to be met for parallel operation of the single phase transformers. ae QN.12 Explain why the no-load current of transformer is non sinusoidal. Why the core of transfor laminated.
