Here are few things Electrical Engineers Knows, that you might not know
- Electricity was never invented. It was discovered.
- Dogs bark at cars’ wheels because the engine produces high-pitch noises that humans can’t hear, but dogs identify as a frightened dog inside.
- Daylight Savings doesn’t actually save electricity. It still exists because it helps the economy.
- Have you ever wondered why birds sitting on a power line don’t get electrocuted? If a bird sits on just one power line it is safe. However, if the bird touches another line with a wing or afoot, it creates a circuit, causing the electricity to flow through the bird’s body. This results in electrocution.
- Enough sunlight reaches the earth’s surface each minute to satisfy the world’s energy demands for an entire year.
- If you wear a gold necklace during an MRI scan, you will burn your neck.
- There is no use in Stealing ceiling Fans and Bulbs in Indian Trains. (Trains Power Supply is at 110 Volts DC. while Our Supply Homes will be of 220 Volts AC in India).
- Pure water will not conduct electricity. But a wet finger will help you get electrocuted easily.
- It is actually safe to sit inside a car during a lightning strike as long as you don’t touch any metal parts!
Explanation: When lightning strikes the car, the outer body being metal acts as a partial Faraday cage (microwave oven is an example of Faraday cage). The outer body carries the charge and through one of the tires, dissipates it to the earth. This keeps the occupants safe inside as long as they don’t touch any metallic parts within the car.
Here’s a photo of the path that lightning takes:
So, in case of any lightning trouble nearby, sit tight in your cars!
- It is not the voltage that kills you, it is the current that kills you.
Explanation: The heart stops (fibrillation) at currents more than 100mA even at regular 230V. The voltage is just a way for the current to flow through the body.
- The current in the tester passes through the human body and to the ground; thus completing the circuit and the LED glows.
This necessitates that for successful checking of an electrical socket, the operator keeps his finger at the metallic tip of the tester.
- The standard aircraft power supply is of 400 Hz and not 50 or 60Hz as is used in domestic/industrial settings around the world.
- The element Selenium conducts electricity only when a light is shined on it. In the dark, it is an insulator.
- The explanation of why the Earth pin is larger and Longer than the Phase and Neutral pins is that
We all know that the earth pin is used to protect the user in the event of a short circuit resulting in the leakage of current through any of the metal regions of an appliance.
(i)If a conductor has a large cross-sectional area the resistance offered by it is a very less hence larger size
(ii) Imagine the following scenario,
A user is holding a plug in one hand and has the other hand in contact with an appliance that has a current leak through the metal body
and is trying to connect it to a live socket(ref above diagram: the switch is already in ON position even before connecting the plug):
If the earth pin is of normal size the user may get electrocuted due to a short circuit and the surge current that may flow through the metal body due to the live socket.
but if it is longer, the earth pin goes and sits in the socket first so whatever current that may flow through the user to the ground will flow through the earth pin to the ground, thus the user is protected.