Electrical Machines If the applied voltage of a certain transformer is increased by 50% and the frequency is reduced by 50%, the maximum flux density will (assuming that the magnetic circuit remains unsaturated) changes to 1.5 times the original value changes to 0.5 times the original value remain the same as the original changes to three times the original value changes to 1.5 times the original value changes to 0.5 times the original value remain the same as the original changes to three times the original value ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Minimum allowable resistivity of power transformer insulating oil is generally taken as 1 X 1012 Ω - cm at 27°C and 0.1 X 1012 2 X 1012 Ω - cm at 27°C and 0.2 X 1012 4 X 1012 Ω - cm at 27°C and 0.4 X 1012 3 X 1012 Ω - cm at 27°C and 0.3 X 1012 1 X 1012 Ω - cm at 27°C and 0.1 X 1012 2 X 1012 Ω - cm at 27°C and 0.2 X 1012 4 X 1012 Ω - cm at 27°C and 0.4 X 1012 3 X 1012 Ω - cm at 27°C and 0.3 X 1012 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In DC machine torque depends on which of the following? both A and B speed flux (φ) armature current (I) both A and B speed flux (φ) armature current (I) ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Saving of copper in auto transformer is increased as compared to two winding transformer, when transformation ratio K approaches to unity. zero. two. infinity. unity. zero. two. infinity. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A dc motor with armature resistance of 0.5 ohms connected directly to a 230 Volt supply. If the armature is stationary then the current flowing through armature is 340 A. 570 A. 460 A. 250 A. 340 A. 570 A. 460 A. 250 A. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A commutator with a diameter of 50 cm rotating at 1000 rpm. For a brush width of 1.5 cm, find the time of commutation in ms. 0.573. 0.443. 0.649. 0.512. 0.573. 0.443. 0.649. 0.512. ANSWER DOWNLOAD EXAMIANS APP
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