The secondary coil is also generating a magnetic field that is growing and shrinking just like the field in the primary coil. This coupling of magnetic energy between these two coils is called mutual induction.

The tendency nowadays is to use synduction or synchronous motors. The synduction motor resembles an induction motor but runs at synchronous speed.

Most building codes require ceiling fans to be mounted on special fan-rated boxes made of metal or strong plastic with deep-threaded holes for the mounting screws. The box must be mounted firmly by attaching it directly to a framing member or using a fan-rated brace.

In an AC circuit, magnetic reversal due to phase difference between current and voltage occurs 50 or 60 times per second. A capacitor helps to improve the power factor by relieving the supply line of the reactive power.

Solder is a fusible metal alloy used to create a permanent bond between metal workpieces. It is made up of 60% tin and 40% lead.

At high temperatures, the tungsten filament gets hot and atoms in the filament vibrate more. The electrons in the current now collide more with the atoms & more energy is needed to push the current through the filament. Hence, the resistance of tungsten increases with temperature.

The mammalian middle ear contains three ossicles, which move the vibrations of the eardrum into waves in the liquid and membrane of the inward ear. There are three ossicles in every ear : Malleus, Incus, Stapes. As we have a couple of ears, so altogether there are 6 ossicles, or 3 sets of ossicles.

Kharif crops – The crops sown in June-July in the Indian subcontinent are called Kharif crops. These crops are harvested in October and November. These require high temperature and humidity at the time of sowing and dry environment at the time of ripening.

Main Kharif crops – Cotton, groundnut, paddy, millet, maize, sweet potato, urad, moong, moth cowpea (Chanwala), jowar, arhar, dhaincha, sugarcane, soybean, okra, sesame, guar, jute, flax etc.