Form factor: The ratio of r.m.s (or effective) value to average value is the form factor (Kf) of the Waveform. It has used in voltage generation and instrument correction factors.
Peak factor: The ratio of maximum value to the r.m.s value is the peak factor (Kp) of the waveform.
Form Factor × Peak Factor = (RMS Value / Average Value) * (Maximum Value / RMS Value) = Maximum Value / Average Value
The efficiency and power factor of single-phase motors are usually low. Thus at full-load a 186 W motor (1/4 hp) has efficiency and poor factor of about 60 percent. For the same size, the single-phase induction motors develop about 50% of the output as that of three-phase induction motors. The starting torque is also low for asynchronous motors / single phase induction motor.
The low power factor is mainly due to the large magnetizing current, which ranges, between 70 percent and 90 percent of full-load current. Consequently, even at no-load these motors have a substantial temperature rise. The power factor of 3-phase motors is of the order of 0.85 lagging, whereas it is 0.55 to 0.6 for single-phase motors.
The relatively low efficiency and power factor of single-phase induction motors is a consequence of their fractional horsepower ratings. The efficiency of 3-phase motors is quite high of the order of 80 to 90 %, while single-phase motors hardly work with an efficiency of 55 to 60 %.
Synchronous motors are not self-starting. The DC source is applied to the rotor of the synchronous Motor.
We use universal motors in mixer grinders. Universal motors can run both on a.c. and d.c.
The universal motor works on the same principle that DC series motor works. DC series motor has the characteristics of operating at high-speed when there is no load and operating at low-speed when the load is applied. It has high starting torque characteristics.
So it is used in mixers, where initially we put some load at starting.
⇒ The electric potential at a point is defined as the work done in bringing the unit positive charge ( +1C) from infinity to that point. The work done is independent of the path taken. Its unit is Volt (V).
⇒ Potential Difference (pd or V) is a measure of the difference in charge between two points in a conductor. Its unit is Volt (V).
⇒ The difference in charge produced by the battery is stored in the battery as electrical potential energy and is called electromotive force (shortened to emf). Electromotive force is also measured in volts. Its unit is Volt (V).
⇒ Electric flux is a measure of how much the electric field vectors penetrate through a given surface. The SI unit of electric flux is N.m2/C.
Electrical potential, Potential difference, Electromotive force has the same SI unit i.e Volt (V). Hence Electric flux is alike from others.
Phosphorus (P) has 15 electron i.e 2,8,5. Hence the number of electron in its outermost orbit is 5.
Silicon (Si) has 14 electron i.e 2,8,4. Hence the number of electrons in its outermost orbit is 4.