Electrical Machines The sparking at the the brushes, in a DC machines is due to reactance voltage. armature reaction. presence of commutator. high resistance of carbon brushes. reactance voltage. armature reaction. presence of commutator. high resistance of carbon brushes. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A smaller air gap in a induction motor helps to reduce the chance of cogging. reduce the magnetizing current. increase the starting torque. reduce the chance of crawling. reduce the chance of cogging. reduce the magnetizing current. increase the starting torque. reduce the chance of crawling. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Quadrature axis synchronous reactance is the ratio of Vmin to Imin. Vmin to Imax. Vmax to Imax. Vmax to Imin. Vmin to Imin. Vmin to Imax. Vmax to Imax. Vmax to Imin. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC series generator, the terminal voltage with increase in load will increase gradually and then stay at rated voltage remain nearly constant decrease increase to rated voltage and then may decrease increase gradually and then stay at rated voltage remain nearly constant decrease increase to rated voltage and then may decrease ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The demagnetising component of armature reaction in a DC generator results in sparking trouble. reduces inter poles flux density. increases armature speed. reduces generator emf. results in sparking trouble. reduces inter poles flux density. increases armature speed. reduces generator emf. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Minimum allowable resistivity of power transformer insulating oil is generally taken as 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 2 X 1012 Ω - cm at 27°C and 0.2 X 1012 1 X 1012 Ω - cm at 27°C and 0.1 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 2 X 1012 Ω - cm at 27°C and 0.2 X 1012 1 X 1012 Ω - cm at 27°C and 0.1 X 1012 ANSWER DOWNLOAD EXAMIANS APP