Q.61 A power transformers used in substations to__
    A. change frequency
    B. step up or step down the voltage
    C. to improve the power factor
    D. to convert AC into DC
Ans.: B

Q.62 For rating up to 10 MVA____ transformers is used.
    A. Naturally cooled oil immersed
    B. naturally cooled oil forced
    C. air forced oil immersed
    D. air force oil circulated
Ans.: A

Q.63 Which of the following instrument transformer is used in substations
    A. CT
    B. PT
    C. Both A and B
    D. neither A nor B
Ans.: C

Q.64 Which of the following is more prone to fault?
    A. Indoor type substation
    B. Underground type substation
    C. Outdoor type substation
    D. all of the above
Ans.: C

Q.65 Indoor substation are usually for a voltage ____.
    A. up to 66 KV
    B. up to 11 KV
    C. up to 33 KV
    D. up to 132 KV
Ans.: B

Q.66 If the surrounding atmosphere is contaminated with impurities like fumes, dust and metal corroding, the indoor substations are erected for voltage up to___
    A. 33 KV
    B. 66 KV
    C. Both A and B
    D. 132 KV
Ans.: C

Q.67 Foundation mounted sub-stations, transformers of capacity __ is used.
    A. below 250 KVA
    B. up to 10 KVA
    C. up to 200 KVA
    D. above 250 KVA
Ans.: D

Q.68 Pole mounted substations, transformers of capacity ____ is employed.
    A. up to 25 KVA
    B. up to 125 KVA
    C. Up to 250 KVA
    D. all of the above
Ans.: D

Q.69 Substations for primary and secondary transmission are ____
    A. pole mounted Indoor type
    B. foundation mounted outdoor type
    C. foundation mounted indoor type
    D. pole mounted outdoor type
Ans.: B

Q.70 Selection and location of site for a substations is depends on___
    A. availability of suitable and sufficient land
    B. Type of substations
    C. Atmospheric conditions and
    D. all of the above
Ans.: D

Q.71 Why aluminum is used for numerous switchgear installation over copper?
    A. higher conductivity on weight basis
    B. lower cost for equal current carrying capacity
    C. excellence corrosion resistance
    D. all of the above
Ans.: D

Q.72 In substations the bus bars are painted or coated with enamel paints because of ____
    A. to indicate different phases in three phase systems
    B. to indicate positive and negative in DC system
    C. Both A and B
    D. to reduce the effective cooling
Ans.: C

Q.73 Why hollow bus bar conductors are used instead of solid one?
    A. due to skin effect
    B. proximity effect
    C. Ferranti effect
    D. all of the above
Ans.: A

Q.74 The bus bar conductors are supported on___
    A. Pin type insulators
    B. Post type insulators
    C. Strain type insulators
    D. Both B or C
Ans.: D

Q.75 ______ which combines the function of the isolators and a switch.
    A. Circuit breaker
    B. load interrupter switches
    C. Earth switches
    D. Line trap unit
Ans.: B