Answer / harsh m upadhyay

the term C.T means current transformer,and the term P.T
means potential transformer.
in ckt where measurements of high voltage and high current
is involved they are used there.
particularly when a measuring device like voltmeter or
ammeter is not able to measure such high value of
quantity because of large value of tourqe due to such
higgh value .it can damge the measuring device.
so, CT and PT are introduced in the ckts.
they work on the same principle of transformer, which is
based on linkage of electro magneticflux produced by
primary with secondary.
they work on the ratio to they are designed.
E.g if CTis of ratio 5000\5A and it has to measure
secondary current of 8000A.
then ANS=8000*5\5000=8A
and this result will be given to ammeter .
and after measuring 8A we can calculate the primary current.
same is the operation of PT but measuring voltage.
WARNING:above information can not be 100% correct.this is
just a opinion after refering various books.no guaranty of
above information.

Answer / avinash koli

SOME TRANSFOMERS ARE KNOWN AS "INSTRUMENTS TRANSFORMER "
AND THEY ARE DEVIDED IN FOLLOWING---
1. C.T. (CURRENT TRANSFORMER )
2. P.T. (VOLTAGE / POTENTIAL TRANSFOMER)

C.T.

IT IS NOTHING BUT STEP UP VOLTAGE TRANSFORMER AND
RELATIVELY STEP DOWN CURRENT TRTANSFORMER .IT IS USED IN
MEASURMENT PURPOSE AS WELL AS PROTCTION PURPOSE OF
TRANSMISSION LINE ....

P.T.

IT IS STEP UP CURRENT TRANSFOMER AND STEP DOWN VOLTAGE
TRANSFORMER . IT IS USED FOR MEASURMENT AND PROTECTION OF
TRANSMISSION LINE....

Answer / khilendra pant

C.T means current transformer,and the term P.T
means potential transformer.we measure current by c.t.&
voltage by p.t.

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