What is a grade rule?
A grade rule is a designated amount a pattern is made larger or smaller at one given point in order to make it fit a range of sizes. A grade rule library is a collection of grade rules that will be used to grade a pattern according to the desired size specifications.
What is the advantage of pattern grading?
The main and one important advantage of this technique is that the newly developed designer pattern retains the size of original basic pattern. Grading in different sizes can be done very easily by flat pattern techniques. It saves the time and energy to be otherwise wasted in making pattern for different sizes.
What is Intersheath grading?
Intersheath grading is the method of keeping the gradual voltage across the insulator by using the layers of the insulators. In this method, the uniform voltage is developed across the cable insulators. The total layer of the insulation material is divided into numbers of layers by providing intersheath.
What is capacitance grading?
Capacitance grading is the process of using various layers of dielectrics with each dielectric having their own permittivity. The permittivity values should be in decreasing order from the surface of the conductor to the sheath of a cable. The uniform dielectric stress cannot be achieved by capacitance grading alone.
How do you calculate capacitance of a cable?
Now, electric intensity Ex at any point P on the considered cylinder is given as shown in the following equations. Then, the potential difference between the conductor and sheath is V, as calculated in equations below. When the capacitance of a cable is known, then its capacitive reactance is given by Xc = 1/(2πfC) Ω.
How many cores are used in a cable for the transmission of voltage upto 66kv?
Three core
What is the most general criterion for the classification of cables?
Classification based upon voltage rating of the cable High tension cables: These have a maximum voltage handling capacity of 11 kV. Super tension cables: These have a maximum voltage handling capacity of 33 kV. Extra high tension cables: These have a maximum voltage handling capacity of 66 kV.
What is the range of super tension cable?
According to voltage these are classified as low-voltage cables for operating voltage up to 1kv, high-voltage cables for operating voltage up to 11KV, super tension cables for operating voltage up to 33 KV, extra high tension cables for operating voltage up to 66KV and extra super voltage power cables for operating …
Which is not type of cables?
In power supply system, there are three wires – Phase(live) wire, neutral wire and earth wire. hence there is no any wire named Zero wire . so correct option is option C.