Development of 11KV/433 volts substation automation using PLC for normal load operation
The maximum generated voltage in power generating stations in advanced countries is 33kV while that in India is _________
The transmission lines and feeders are _____________ .
The transmission lines are _____________
________ are lines conductors which connect the distribution substations to the areas, to be fed by those distribution substations.
________ are the terminals which connect the consumer�s terminals to the distributors
In AC-system ,
In AC system,
Statement 1:- The best method is to use AC system for generation and distribution purpose and DC system for transmission purpose.
Statement 2:- The best method is to use DC system for generation and distribution purpose and AC system for transmission purpose.
Statement 2:- The best method is to use DC system for generation and distribution purpose and AC system for transmission purpose.
Underground cables are rarely used for
Important component of overhead lines is
The characteristics that conductors used for transmission and distribution should posses :
Hard drawing of copper __________ electrical conductivity by small amount but it ___________ the tensile strength considerably.
Copper conductor is
Aluminium is ______________ in weight as compared to copper, but has _________ conductivity and tensile strength.
The sag in aluminium conductors is __________ the copper conductors.
The advantages of using aluminium conductors steel reinforced over aluminium conductor is ________
Choose the proper set of increases order of mechanical strength of the following line supports :
Characteristics of an insulator used in overhead lines are
A good porcelain insulator has compressive strength of about _________ and dielectric strength of _________ of its thickness.
Glass insulators, can be used up to _________ under normal atmospheric conditions, and in dry atmosphere, it can be used up to __________ .
Steatite is produced by mixing ___________ with small proton of ________ and ___________.
In a pin type insulator,
The factor affecting the sag in overhead lines are
Due to skin effect, the total resistance of the conductor _________, as the frequency of the current ________ and also with the increases in the diameter of the conductor.
The skin effect is negligible when the supply frequency is ________ and the conductor diameter is _________.
The alternating magnetic flues in a conductor caused by the current flowing in a neighbouring conductor gives rise to circulating currents which cause an apparent increases in the resistance of the conductor. This phenomena is called ________ .
The factor which effect skin and proximity effects are ______________
Usually in short transmission lines ___________
In medium transmission lines
In long transmission lines
In oil circuit breaker (O.C.B) the range exists between
Advantages of using Air blast Circuit breakers:
In SF6 Circuit breaker
The voltage across the contacts during the arcing period is known as _______
The transient voltage appearing across the contacts during arc period is called ________
When low inductive current is interrupted by a Circuit breaker and the arc generating force of the Circuit breaker and is more than necessary to interrupt a low magnitude of current, the current will be interrupted before its natural zero instant. It is termed as
_______ is the r.m.s value of current which the Circuit breaker is capable of carrying continuously at its rated frequency under specified conditions.
The peak value of current (including the DC component) during first cycle of current wave after the closure of Circuit breaker is known as __________.
__________ is the current (r.m.s value) that a Circuit breaker is capable of breaking under specified conditions and given recovery voltage.
__________ of a Circuit breaker depends upon its ability to withstand the temperature rise and the electromagnetic force effects.
Advantage of using instrument Transformer is
Instrument transformers are classified as:
Potential transformers are made with
Potential transformers are carefully designed to ensure
A high magnitude alternating current can be measured by a combination of _________ and_________.
The current transformer ratio is not equal to the ratio of secondary to primary turns.
_________is used to make sure that an electrical circuit can be completely de-energized for service or maintenance.
The major difference between an isolates and a circuit broken is that
Gas Insulated Switchgear (GIS) offers
The space requirement of Gas Insulated Switchgear (GIS) can be less than ______ of the space taken up by an equivalent conventional installation.
A ______ is a substation which does not contain transformers and operates only at a single voltage level.
The apparatus used for switching, controlling and protecting the electrical circuit and equipment is known as
Switchgear consist of:
Functions of switchgear are
Essential features of switchgear are
__________ is a hollow insulating lines through which a conductor may pass .
Small porcelain bushing can be used up to _________
The inside of the bushing may contain __________ and the bushing is often filled with ________ to provide additional insulation.
Bus bar can be arranged in ____________
The major advantage of single bus-bar system is that fault on one part of the bus'bar or system does not completely shut down the whole station.
_________ is a device which is used to switch from one bus to the other without any interruption in power supply and without creating hazardous arcs.
Lighting arrestor are also called as __________