Electrical Machines When R2 is rotor resistance, X2 the rotor reactance at supply frequency and s the slip, then the condition for maximum torque under running condition will be R2 = sX2. R2 = s2X2. R2 = s2X2. sR2 = X2. R2 = sX2. R2 = s2X2. R2 = s2X2. sR2 = X2. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If residual magnetism of a shunt generator is destroyed accidentally it may be restored by connecting its shunt field in reverse. to a DC source. to earth. to an AC source. in reverse. to a DC source. to earth. to an AC source. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If a DC motor is connected across the AC supply it will Not run. Burn. Run at lower speed. Run at normal speed. Not run. Burn. Run at lower speed. Run at normal speed. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following machines have highest power factor with respect to magnetizing current? Closed slot type machines. Open slot type machines. Semi closed slot type machine. Any of the above. Closed slot type machines. Open slot type machines. Semi closed slot type machine. Any of the above. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Minimum allowable resistivity of power transformer insulating oil is generally taken as 4 X 1012 Ω - cm at 27°C and 0.4 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 3 X 1012 Ω - cm at 27°C and 0.3 X 1012 4 X 1012 Ω - cm at 27°C and 0.4 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 3 X 1012 Ω - cm at 27°C and 0.3 X 1012 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC machine the armature mmf is rotating with respect to field poles. stationary with respect to field poles. stationary with respect to armature. rotating with respect to field poles as well as armature. rotating with respect to field poles. stationary with respect to field poles. stationary with respect to armature. rotating with respect to field poles as well as armature. ANSWER DOWNLOAD EXAMIANS APP