A 10-pole, , single phase induction motor runs at  while driving rated load. The frequency of induced rotor currents due to backward field is

The type of single-phase induction motor, expected to have the maximum power factor during steady state running condition, is

The equivalent circuit of a single phase induction motor is shown in the figure, where the parameters are and S is the slip. At no-load, the motor speed can be approximated to be the synchronous speed. The no-load lagging power factor of the motor is ________ (up to 3 decimal places).  

A 375 W, 230 V, 50 Hz, capacitor start single-phase induction motor has the following constants for the main and auxiliary windings (at starting):  (main winding),  (auxiliary winding). Neglecting the magnetizing branch, the value of the capacitance  to be added in series with the auxiliary winding to obtain maximum torque at starting is

The direction of rotation of a single-phase capacitor run induction motor is reversed by

A three-phase slip-ring induction motor, provided with a commutator winding, is shown in the figure. The motor rotates in clockwise direction when the rotor windings are closed. 

If the rotor winding is open circuited and the system is made to run a rotational speed  with the help of prime-mover in anti-clockwise direction, then the frequency of voltage across slip rings is  and frequency of voltage across commutator brushes is . The values of  respectively are

A single phase induction motor is provided with capacitor and centrifugal switch in series with auxiliary winding. The switch is expected to operate at a speed of 0.7Ns, but due to malfunctioning the switch fails to operate. The torque-speed characteristics of the motor is represented by

In a single phase induction motor driving a fan load, the reason for having a high resistance rotor is to achieve

The type of single-phase induction motor having the highest power factor at full load is

A single-phase, 230 V, 50 Hz, 4 pole, capacitor-start induction motor has the following stand still impedances

Main winding =6.0 + j4.0Ω

Auxiliary winding = 8.0 + j6.0Ω

The value of the starting capacitor required to produce 90° phase difference between the currents in the main and auxiliary windings will be

A single phase induction motor with only the main winding excited would exhibit the following response at synchronous speed