[amp_mcq option1=”high inductance of field and armature circuits” option2=”induced current in rotor due to variations of flux” option3=”series motor is connected to A.C. supply, the power factor will be low because of A. high inductance of field and armature circuits B. induced current in rotor due to variations of flux C. fine copper wire winding” option4=”none of the above” correct=”option1″]<\/p>\n
The correct answer is: A. high inductance of field and armature circuits<\/p>\n
When a DC series motor is connected to an AC supply, the inductance of the field and armature circuits causes the current to lag the voltage. This lagging current results in a low power factor.<\/p>\n
The inductance of a coil is a measure of its opposition to changes in current. When an AC voltage is applied to a coil, the current will lag the voltage because the coil takes time to build up a magnetic field. The inductance of the field and armature circuits in a DC series motor is high, which causes the current to lag the voltage.<\/p>\n
The power factor is a measure of how efficiently a circuit converts electrical energy into mechanical energy. A power factor of 1 indicates that all of the electrical energy is converted into mechanical energy. A power factor of less than 1 indicates that some of the electrical energy is lost as heat.<\/p>\n
The low power factor of a DC series motor connected to an AC supply is caused by the inductance of the field and armature circuits. This lagging current results in a loss of power, which can be reduced by using a power factor correction device.<\/p>\n","protected":false},"excerpt":{"rendered":"
[amp_mcq option1=”high inductance of field and armature circuits” option2=”induced current in rotor due to variations of flux” option3=”series motor is connected to A.C. supply, the power factor will be low because of A. high inductance of field and armature circuits B. induced current in rotor due to variations of flux C. fine copper wire winding” … <\/p>\n