The first post

THE FIRST POST

First of all before starting anything I would like to say that I have not any experience with blogging or something like that. So I strongly apologize from all of you for any of my mistake.

Now, Why I have created this, the simple answer for this is to spread the knowledge of science and technology to others which i have gain from others. This blog is just a medium or a platform which provide all of these. There are lots of things which must an engineer or an engineering student know and here these all things will be.

So lets start.....................

NOTE: IT IS A PINNED POST SO ALL THE NEW POSTS WILL BE BELOW THIS.

How does a refrigerator works?

Second Law of Thermodynamics states that if a cold object is placed near a hot object, the temperature of colder object will rises and the temperature of warmer object will fall.

so how it practically works..............

It works on principal of cooling through evaporation.

An evaporating gas called refrigerant draws heat from the surrounding and make it cold.
there is a compressor which imparts high pressure to the refrigerant (pure Ammonia is used commonly which evaporates at -32 Celsius). Due to this high pressure its temperature increases and it becomes hot. This heated gas flow through the coil, behind the refrigerator which allows excess heat to be released in surrounding (this is the reason of feeling warmer around the fridge).

eventually the ammonia cools down to the point where it becomes liquid. then it passes through an expansion valve.due to a very small opening the liquid ammonia is turned into a very cold, fast moving mist.Since this evaporation occur at -32 Celsius the ammonia draw heat from the surrounding.
This the second law of thermodynamics where the cold ammonia take heat from the object which is placed in refrigerator (say a water bottle) and makes the object cooler. As it takes heat it temperature rises and then this warm ammonia is returned back to compressor and the cycle continues where the pressurization, evaporation and cooling begins.

Why the earth pin is made bigger in a three pin plug

first of all know the reason for this third pin.

when we use an appliances of metal body there is a chance of possible electric shock due to some charge leakage inside the appliance.
hence to prevent electric shock there proper earthing is required which is done by this third pin.

Now the reason behind making this pin bigger.
Earth pin is longer than the others which means it is first to connect as well as last to disconnect.

• when inserting the plug, the earth connection is made before the current carrying contact of the plug become live.

• when removing the plug, the current carrying contact separate before the earth connection is separate. 

Thus it is always made to improve safety.

what the fuse actually protect.

Consider the following simple circuit:

There are basically five components in the above circuit i.e 9 V battery, Fuse, Switch, Lamp and the connecting wire.

Which component is fuse protecting in the circuit ?

If you think that it is the lamp load then you are incorrect. It is actually the wires that fuse protects because it is the one that is actually carrying the current whereas lamp is drawing the current supplied by the battery source. Thus the primary function is to protect the wire though it will at the same time avoid damages to the load due to overcurrent.

#AAYUSH BHARDWAJ

The zero Watt bulb, Nothing is ZERO.

It is called as zero watt but actually it is not. it is. These small Incandescent bulb have power rating of 10 to 15W.

In the earlier day electro mechanical energy meters are used instead of digital meters to record the energy consumption.

Electrical consumption was recorded by counting revolution of a disc through mechanical counters and for this a minimum current is required to be flowed through the meter. Now the current drawn by these bulb is very small to grt the disc rotating and hence the energy consumption is not recorded by these electro mechanical energy meter.

Hence it seems that bulb have no power consumption and hence they got the name zero watt bulb.

Now with the digital meters even a small current drawn by 0.1V LED is also detected and hence the zero watt bulb is a misnomer

#AAYUSH BHARDWAJ

Latest technology in mechanical engineering

Tesla electric car

Most of the electric vehicles failed because of poor design structure, safety feature, charging infrastructure, etc. They worked splendidly on every failure of their rival forerunners. Tesla models are not hybrid, they are fully electric.

Fuel cell cars - The Mirai

Self driving Car

Google’s self driving car is almost driverless(manual assist needs in some dangerous turns) with start and stop option and which uses chauffeur system. The LIDAR(combined SONAR and RADAR) technology with Google map works in a precision manner. It uses 64 typical laser beams to find the objects around the car (360 degree). Cost of this system is around US $ 1 lakh. Accuracy, precision is more in this system which enables pre safe. Top speed is 40 kmph.

Honda Self balancing Motorcycle

Honda revealed a motorcycle that can run without being controlled by the driver and balanced by itself without fall in Consumer Electronic show(CES), Las vegas.

The new technology was developed by Honda to eradicate low-speed accidents. The motorcycle will even follow its rider when the rider is not sitting on the motorcycle.

The digital system that senses the low-speed below 3 miles per hour, disengages the handlebar from the front forks and computer takes it to control.Generally, the self-balancing technology uses gyroscopes but they add a lot of weight. Instead, Honda's Riding Assist system increases the rake angle the front forks and disconnects the handle bar. it then uses minute steering inputs to keep the bike perfectly balanced.

It reduces the center of gravity to improve the stability to withstand without falling.

It's following the rider by the sensing technology.if you want to get parking the vehicle go to the place where you want to park.

Hope it will reduce the accident and improve the rider safety.

Netherlands-based PAL-V Europe NV has bagged a patent in India a two-seat hybrid car and gyroplane Back to the future: flying car in India

Those who were amused by the flying car that knocked at the window of Harry Potter, can now look forward to a real flying car knocking at their door in the future.

The Netherlands-based PAL-V Europe NV has bagged a patent in India for the Personal Land and Air Vehicle (PAL-V), a flying car that can also run on roads. The car made its successful maiden flight in The Netherlands in 2012 and the company has been developing PAL-V One, a two-seat hybrid car and gyroplane with the convenience of fully integrated door-to-door transportation.

#AAYUSH BHARDWAJ

How exactly the electric line tester works.

What here I am going to write is very basic but interesting.

Every common man (who uses electricity) knows what is the Tester & how to use it.

But most of the people don’t know how exactly it works?

When we touch mouth (flat end of the Metallic rod) of Phase or Line tester with naked Live / hot wire whereas one of our finger touch the metallic Cap Screw or Clip of Phase/Line Tester  then circuit is completed and current start to flow in Metallic rod.

Metallic rod is connected to the resistor which reduces high current to a safe value. The reduced Current passes through Neon bulb which is connected to (metallic spring) . Metallic spring is connected with metallic Cap screw which is in contact of our fingers. A very small current passes through our body to earth and complete the circuit. When circuit is completed, current starts to flow and the filament of neon bulb starts glowing. One thing which is important here is that the neon lamp takes very little current to light, and thus can use the user's body impedence to earth ground to complete the circuit.This indicates that the touched wire with Phase/Line Tester mouth is Phase/Line/Hot.

If we perform the same action as mentioned above, and Neon bulb does not glow, it means that is a Neutral Wire/Conductor and Neon bulb does not glow, it means that  it is a neutral wire/ conductor.

These types of currents, which does not cause any harm to our body are called as “let go currents”. (For women, it is typically 5 to 7 milliamperes, and for men, typically 7 to 9 milliamperes. This is dependent on the muscle mass of the individual.)

.

Try doing this:

1.     Stand on plastic/wooden chair.

2.     Insert tester in socket, with one of your fingers touching end of tester.

3.     Switch ON the supply.

If you follow above steps you will find, light inside tester illuminates but intensity is quite low. Because additional resistance gets added in circuit.

That’s all!

#AAYUSH BHARDWAJ