When two alternating quantities of the same frequency have different zero points, they are said to have a phase difference. The angle between zero points is the angle of phase difference φ. In the above-given question, the frequency of voltage and current is different so we can’t calculate the phase difference between them
The stroboscopic effect is a visual phenomenon that happens when a blinking light source glows an object in movement, generating a sequence of samples. The stroboscopic effect is based on Illuminance hence it is not related to the transmission and distribution of electric power.
While estimating the overhead lines, the first and last pole is always earth connected and after every 3rd electrical pole, the fourth pole is earthed. Therefore, the approximate number of required ground set = 4
A single-phase induction motor with only one winding on the stator cannot produce any starting torque. Hence, some extra arrangement is required to start the motor. In the running condition, the motor is capable of developing the torque with only one winding on the stator. The simplest method of starting is to provide an auxiliary winding on the stator in addition to the main winding. The two windings are placed in the stator with their axes displaced by 90 electrical degrees in space.