1. Did you ever notice gravel beneath and around large transformers (like in the pic)?
One of the reasons for this practice is actually “snakes”. Yes, you read it right.
Large transformers produce substantial vibrations due to magnetostriction which get transmitted to ground. Due to this effect the transformers placed on solid ground attract snakes. To prevent this, transformers are surrounded by gravel which prevents snakes from coming near it.
2. A common ceiling fan (not the BLDC ones) can actually rotate in either direction. It is the capacitor that makes it run in a specific direction (clockwise or anticlockwise). If you just remove the capacitor and complete the remaining circuit you can make it run in either direction by giving it a gentle push.
3. You can estimate the transmission voltage in overhead lines by merely counting the number of insulator disks used to support the wires.
Each of such disks can withstand 11 kV of voltage. So in case you see 3 disks then you can safely deduce that the transmission voltage can be around 33 kV.
4. If you look at transmission line you might find small devices like the one in the image below.
They are called Stockbridge Dampers. They are usually present as a pair on either side of a pole/suspension point. They are used to dampen out vibrations produced in transmission lines.
5. Zebra, Dog, Peacock, Moose, Dog, Hen are also names for transmission line conductors. They differ from each other in terms of size, number of strands, material used, etc.
6. About 70% of the electricity produced in the world is actually consumed by Induction Motors. Their ruggedness, easy speed control, nil maintenance requirement makes them the most commonly-used motor.
7. Hydro Power Plants are actually a necessity in today’s electrical grid network. In their absence, the electrical grid will become highly susceptible to load variations and collapse on occurrence of a moderate load variation on the consumer end. It is because these hydro turbines increase the inertia of the power system which protects it from sudden jerks due to load variations.
EDIT 1 :
8. Magnetic field strength developed inside a transformer core ranges from 1.5 to 1.6 tesla. It is very large in comparison to the magnetic field strength of Earth or the Sun.
Earth’s magnetic field is of the order of a microtesla. Whereas the Sun’s magnetic field ranges from 0.1 to 100 milliteslas.
9. You must have seen that overhead transmission lines are laid with a sag in them.
The sag is not introduced instinctively. It is mathematically calculated to determine the height of the middle point of the conductor from the ground keeping in mind the effect of wind, temperature, frost, and other types of condensation.
EDIT 2 :
10. Electromagnetic isolation for a device can be achieved by placing it in a metallic enclosure. Same principle works in a Faraday’s Cage to protect a person from high voltages.
Sometimes line maintenance workers have to work on active transmission line to prevent loss of power. The workers are directed to wear Faraday’s Suit then to prevent electrocution from induced currents in their tissues due to high strength electrical and magnetic fields.
The suit is in effect a wearable Faraday cage, which equalizes the potential over the body, and ensures there is no through-tissue current. The strong electric field surrounding charged equipment is enough to drive a current of approximately 15 μA for each kV·m−1 through a human body. To prevent this, hot-hand workers are usually required to wear a Faraday suit.
-WIKIPEDIA : Live-line working – Wikipedia
11. The shaft of a 2 pole 3 phase synchronous generator, in power stations, operating at 60 Hz can spin at 3600 rev/min.
The blades of your humble kitchen juicer & grinder rotate at a whopping 20,000 rev/min. They utilize either a DC or a Universal motor. So it goes without saying that you must keep your fingers out of them.
As an interesting comparison, the cricketing legend Shane Warne is able to spin the cricket ball at around 5000 rev/min. I bet he can make one hell of an orange juice.
PS: Reducing Step Potential and Touch Potential are the main reasons for using gravel beneath transformers. The use of gravel grants us many other benefits too. Deterring snakes is ONE OF THEM.