1. Instrument transformer is used for
(A) For the protection of meters
(B) Both b & c
(C) To increase the range of DC meters
(D) To increase the range of AC meters
2. Types of Instrument transformer are
(A) 02
(B) 03
(C) 04
(D) 05
3. The advantage of using instrument transformer is
(A) Safety of operator from the danger of high voltage
(B) All these
(C) More than one meter on a single transformer
(D) Small size meters for high voltage and high current
4. Secondary current of current transformer is usually
(A) 15A
(B) 10A
(C) 05A
(D) 02A
5. Secondary voltage of voltage transformer is usually
(A) 220V
(B) 12V
(C) 400V
(D) 110V
6. Number of primary turns of a current transformer are
(A) Few
(B) One
(C) Large
(D) Any of a or b
7. Sometimes this is used as primary winding of a current transformer
(A) Secondary winding
(B) Load cable
(C) Transformer core
(D) None of these
8. If primary current is more than 100 amperes, then its core is made in this shape
(A) Rectangular shaped
(B) Square shaped
(C) Circular
(D) All these
9. This bears more resemblance to power transformer
(A) Potential transformer
(B) Current transformer
(C) Auto transformer
(D) None of these
10. Clamp on meter is basically a
(A) Non split core CT with ammeter
(B) Split core PT with voltmeter
(C) Split core CT with ammeter
(D) Transformer and rectifier
11. Ratio error of a CT means that the secondary current (with reference to the turn ratio) becomes
(A) Slightly less than that it should be
(B) Slightly greater than that it should be
(C) Zero
(D) Equal to the primary current
12. A C.T has few ampere turns, so its weight may be
(A) Few grams
(B) From 01Kg to many tons
(C) Up to one kilogram
(D) Both a & b
13. Usually it is attached with clamp on meter
(A) All these
(B) Volt meter
(C) Frequency meter
(D) Ampere meter
14. The ratio between rated primary current and rated secondary current of a C.T is called
(A) Phase angle error
(B) Ratio error
(C) Nominal transformation ratio
(D) Actual transformation ratio
15. Transformation ratio received in case of loaded C.T is called
(A) Nominal transformation ratio
(B) Actual transformation ratio
(C) Turn ratio
(D) None of these
16. The ratio between actual and nominal transformation ratio is called
(A) Ratio correction factor
(B) Ratio error
(C) Power correction error
(D) Both b & c
17. Burden of a C.T is stated in
(A) Amperes
(B) Volts
(C) Watts
(D) Volt amperes
18. Rated burden of a C.T may be
(A) 1.5VA
(B) 5VA
(C) 30VA
(D) Any of these
19. Phase angle of a C.T depends upon
(A) Magnetising component of no load current
(B) Total value of no load current
(C) Iron loss component of no load current
(D) Load current
20. Reason of phase angle error in a C.T is
(A) No load current
(B) Iron loss component of no load current
(C) Magnetising component of no load current
(D) Primary current
21. Phase angle error of a C.T can be reduced by
(A) All these
(B) Reducing the leakage of flux in the core
(C) Using the core material having high permeability
(D) Reducing the flux density in the core
22. To reduce the ratio error in C.T
(A) Secondary turns are slightly increased
(B) Secondary turns are slightly reduced
(C) Core is made in circular form
(D) Core is made from non magnetic material
23. C.T may be of this type
(A) Ring type
(B) Bushing type
(C) Split core type
(D) All these
24. Secondary current of a C.T depends upon
(A) All these
(B) Primary load current
(C) Type of C.T
(D) Secondary burden of C.T
25. By increasing the secondary current of C.T, its error will
(A) Become less
(B) Become more
(C) Not change
(D) Become zero
26. By increasing the burden of a C.T, its errors will
(A) Decrease
(B) Become zero
(C) Increase
(D) Not be effected
27. If primary current of a C.T is very small then
(A) Both phase angle error and ratio error will be high
(B) Its phase angle error will be high
(C) Its ratio error will be high
(D) No effect on errors