Answer / jatin sharma

generally the current at the time of fault is more than 5
times the normal current and hence is thicker

Answer / jagannath seth

In a three pin plug two pins look same. One of them is connected to phase(live wire).Their connection may be interchanged. The third pin (which is thicker) passes the induced current or leakage current and thus make an electrical instrument safe. In no condition positive current should be passed through the thicker pin.If passes, safety of the instrument will be disturbed.That is why the third pin is made thicker so that one can't connect it to positive current by mistake.

Answer / sarthak dalal

When we use electrical appliances with metal bodies, we require protection against possible electric shock. If there is a fault current (leakage) inside the appliance, the whole metal case becomes live. If you happen to touch it, a current will flow through you to the earth (ie. electric shock). Hence, to prevent electric shock, we need to ensure that the system is properly earthed (= 'grounded'). This way if you touch a faulty appliance, you don't get electrocuted!



So, why is the earth pin made bigger?

1. The earth pin on a plug is longer than the live and neutral pins. This means the earth pin is the first to connect and the last to disconnect.

When inserting the plug, the earth connection is made before the current carrying contacts of the plug become live.
When withdrawing the plug, the current carrying contacts shall separate before the earth connection is broken.
Thus, the earthing connection is always maintained to improve safety.

2. Many wall sockets have safety shutters (see image) on the live and neutral lines to prevent children from inserting conducting materials which may result in electric shock. Insertion of a longer (earth) pin helps in opening the shutters, facilitating the insertion of other two pins. These are called Earth-pin operated shutters.



3. Though it is impossible to insert the plug into the socket upside down, one may try to insert the plug top in a misaligned position (for e.g. trying to insert the earth pin into the phase socket with the other two pins further down out of the socket). Hence, the earth pin is made thicker so that even by mistake it cannot be inserted into the live or neutral hole of the socket. This prevents earth pin from establishing an electrical contact with the live terminal.

As you can see, every effort is taken to protect you from electric shock.

Answer / sandeep chaudhary

We know that R=९l/A so if cross section area is increases R will decrease. And if by mistake live is connect before earth pin then to protect yourself maximum current will flow through earth pin.

Answer / arpan

so that you are well knowm by all the three points otherwise there will be a shorg circjit in a device

Answer / rajesh

If leakage current or negative sequence current happens in a
particular system,they cause severe damage in that
system.for prevent that system we provide less resistance
path(r=pl/a).if resistance is inversely propotional to
area.we use large size cable.

Answer / mechsatheesh

i think whenever you insert a plug in plug board it should
keep contact quickely,first than other two lower pins for
providing quick earth contact,....

Answer / prabhakar

because of socket earth hole is big. & one more reason is
its fix very tigt.loose contact doesn't happend

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