Electrical Conductivity of Materials

It is the property of material which represents that how easily the electricity can be conducted by the material. It is denoted by ‘σ’. It is the reciprocal of resistivity of material. It unit is mho/meter.

Please don't hesitate to use those buttons.

Which of the following could be lamina-proximately the thickness of laminations of aD.C. machine ?
anonymous poll

(c) 0.5 m – 18
👍👍👍👍👍👍👍 42%

(b) 0.05 mm – 13
👍👍👍👍👍 30%

(a) 0.005 mm – 9
👍👍👍👍 21%

(d) 5 m – 3
👍 7%

👥 43 people voted so far.

The armature of D.C. generator is laminated to?
anonymous poll

(d) reduce eddy current loss – 51
👍👍👍👍👍👍👍 69%

(a) reduce the bulk – 14
👍👍 19%

(b) provide the bulk – 6
👍 8%

(c) insulate the core – 3
▫️ 4%

👥 74 people voted so far.

Answer on the base of your knowledge, don't google!

The amount of damage done by the electric shock depends not only on the magnitude of the current.

Electricity travels at the speed of light -- more than 186,000 miles per second!

Lightning is a discharge of electricity in the atmosphere. Lightning bolts can travel at around 130,000 miles per hour and reach nearly 54,000 °F in temperature.

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 a foot, it creates a circuit, causing the electricity to flow through

Coal is the world’s biggest source of energy for producing electricity. Coal is burned in furnaces that boil water. The steam from the boiling water then spins turbines that are attached to generators.

Did you know that electricity plays a role in the way your heart beats? Electricity causes muscle cells in the heart to contract. Electrocardiogram (ECG) machines, used by medical professionals, measure the electricity going through the heart. As the heart

Electric fields work in a similar way to gravity. Whereas gravity always attracts, electric fields can either attract or repulse.

Benjamin Franklin carried out extensive electricity research in the 18th century, inventing the lightning rod amongst his many discoveries. In the event of a lightning strike, the lighting rod conducts the strike through a grounded wire, protecting the building.

Two positive charges repel each other, as do two negative charges. On the other hand, opposite charges attract each other.

removed inactive members..

Factors Affecting Corona in Power System
As mentioned earlier, the line voltage of the
conductor is the main determining factor for corona
in transmission lines, at low values of voltage (lesser
than critical disruptive voltage) the stress on the air
is too less to dissociate them, and hence no
electrical discharge occurs. Since with increasing
voltage corona effect in a transmission line occurs
due to the ionization of atmospheric air surrounding
the cables, it is mainly affected by the conditions of
the cable as well as the physical state of the
atmosphere.

coming back soon..

Methods of Arc Extinction in Circuit Breaker


High resistance method

Low resistance or current zero method.

What is Circuit breaker?

Circuit breaker is a switching device which can be operated manually as well as automatically for controlling and protection of electrical power system respectively. 

The Circuit Breakers according to the voltage levels they can operate on :

1.Low Voltage Circuit Breakers (< 1 kV)

2.Medium Voltage Circuit Breakers (1-72 kV)

3.High Voltage Circuit Breakers (> 72 kV)

Very important category is where to use the circuit breakers:

1.Outdoor circuit breaker

2.Indoor circuit breaker

There is another category which is based on the mechanism used to actuate the circuit breaker, which specifies the mechanism of operation of the breaker, there are three further types:

1.Spring operated circuit breaker

2.Pneumatic circuit breaker

3.Hydraulic circuit breaker

Now considering the medium in which a circuit breaker can operate:

1.Oil circuit breaker.

2.Air Blast circuit breaker.

3.SF6 circuit breaker.

4.Vacuum circuit breaker.