Electrical Machines When a short circuit test on a transformer is performed at 25 V, 50 Hz, the drawn current is I1. If the test is performed by 25 V and 25 Hz and power drawn current is I2, then I1 = I2 None of these I1 > I2 I1 < I2 I1 = I2 None of these I1 > I2 I1 < I2 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A transformer has maximum efficiency at 3/4 load. The ratio of iron loss and full load copper loss is 3/4. 16/9. 9/16. 4/3. 3/4. 16/9. 9/16. 4/3. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Two synchronous generators operating in parallel 200 MW and 400 MW respectively. The drooping characteristics of their governors are 4% and 5% from no load to full load. Consider the governors operating at 50Hz on no load. How will the machine share, if the load is 600 MW? 200 MW and 400MW None of these generator 1 gets over load generator 2 gets over load 200 MW and 400MW None of these generator 1 gets over load generator 2 gets over load ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The results of a slip test for determining direct axis (Xd) and quadrature axis (Xq) reactances of a star connected salient pole alternator are given below Phase values: Vmax = 108 V ; Vmin = 96 V Imax = 12 A ; Imin = 10 A Hence the two reactances will be Xd = 8Ω and Xq = 10.8Ω Xd = 10.8Ω and Xq = 8Ω Xd = 9Ω and Xq = 9.6Ω Xd = 9.6Ω and Xq = 9Ω Xd = 8Ω and Xq = 10.8Ω Xd = 10.8Ω and Xq = 8Ω Xd = 9Ω and Xq = 9.6Ω Xd = 9.6Ω and Xq = 9Ω ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For a specific open-circuit voltage of a DC generator, the short-circuit electric current will be maximum when it is shunt connected. separately excited. differentially compounded. cumulatively compounded. shunt connected. separately excited. differentially compounded. cumulatively compounded. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Compensating windings are used in DC generators to provide path for the circulation of cooling air. None of these to neutralize the cross magnetizing effect of the armature reaction. mainly to reduce the eddy currents by providing local short circuit. to provide path for the circulation of cooling air. None of these to neutralize the cross magnetizing effect of the armature reaction. mainly to reduce the eddy currents by providing local short circuit. ANSWER DOWNLOAD EXAMIANS APP