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 0.7 Ns, but due to malfunctioning the switch fails to operate. The torque-speed characteristic of the motor is represented by

The torque-speed characteristics of motor ($$T_M$$) and load ($$T_L$$) for two cases are shown in the figures (a) and (b). The load torque is equal to motor torque at points P, Q, R and S The stable operating points are

In a synchronous machine, hunting is predominantly damped by

A hollow metallic sphere of radius r is kept at potential of 1 Volt. The total electric flux coming out of the concentric spherical surface of radius R(>r) is