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1.0.0
MCQ
3701. সার্জ ভোল্টেজ মাটিতে পাঠানোর জন্য কোন ডিভাইস ব্যবহার করা হয়?
Earthling screen
Lightning arresters
Overhead ground wire
All
3702. The relay operation coil is supplied through-
fuse
power transformer
current transformer
none
ব্যাখ্যা: The relay operating coil is supplied through current treansformer. Current transformer is used to measure the current as the indication for relay.
3703. বাংলাদেশে কয়টি ন্যাশনাল গ্রিড লাইন আছে?
1 টি
3টি
2টি
4টি
3704. Differential relay is used for protection of--
Transmission line
Equipment having windings
Distribution line
None
3705. An isolator is designed to open a circuit--
full load
normal condition
no load
all of the above
ব্যাখ্যা : An isolator is designed to open a circuit under no load Its main purpose is to isolate one portion of the circsil from the other and is not intended to be opened while current is flowing in the line
3706. ফিডার লাইনে বুস্টার ব্যবহার করা হয় কেন?
পাওয়ার বাড়ানোর জন্য
ভোল্টেজ বাড়ানোর জন্য
পাওয়ার ফ্যাক্টরের মান বাড়ানোর জন্য
ভোল্টেজের সমতা করার জন্য
3707. A fuse is a--
protective device
current limiting device
current controling device
none of the above
ব্যাখ্যাঃ in electronic and electrical engineering, a fuse is an electrical safety or protective device, that operates provide overcurrent protection of an electrical circuit
3708. Breaking current is a value.
RMS
Maximum
Average
Any of the above
3709. Under normal operating conditions, the contacts of the circuit breaker remain-
closed
semiclosed
open
none of the above
ব্যাখ্যা: Under normal operating conditions, the contacts the circuit breaker remain closed. When any fault occart the contact is opened.
3710. Which of the following circuit breaker is highly reliable and has a least maintenance?
Oil circuit breakers
Air blast
Vacuum circuit breakers
SF6 circuit breakers
3711. SF6 gas is used as it has-
High-boiling point
Electronegativity
Good conductivity
None
3712. IDMT relays are used to protect the power transformers against-
External short-circuit
Overloads
Internal short-circuits
Both (a) and (b)
3713. Lightning current-এর range কত?
2kA-5kA
10kA-90kA
10kA-50kA
None
3714. A permeable substance is one--
Which is a good conductor
Which is a band conductor
Which is a strong magnet
Through which the magnetic lines of force can pass very easily
3715. Substation-এ কোন ধরনের ট্রান্সফর্মার ব্যবহৃত হয়?
Step up
Step down
Both ক&খ
None
ব্যাখ্যা: উচ্চ ভোল্টেজকে সাবস্টেশনে স্টেপ ডাউন ট্রান্সফর্মারের সাহায্যে গ্রাহক উপযোগী করে বিতরণ করা হয়।
3716. 8A generator supplies 100 MVA at 0.5 power factor. What is in MW?
100
90
200
None
3717. Horn gap লাইটনিং অ্যারেস্টার কোন আকৃতির হয়ে থাকে?
আয়তাকার
গোলাকার
গরুর শিং-এর আকৃতির
কোনোটিই নয়
3718. Fault level means-
fault current
fault MVA
voltage at the point of fault
none
3719. Primary winding of CT is connected--
In series with the load
In parallel with the load
Between line and neutral
Both (a) and (b)
ব্যাখ্যা: The primary winding of the current transformer(CT) is connected in series with the transmission line whose current is to be measured where the potential transformer (PT) is connected in parallel with the line
3720. Most faults occurring in the field are in-
CTs and PTS
switchgears
overhead lines
cables
ব্যাখ্যা: Most faults occuring overhead lines. Because in raining day, there is more probability to occur fault. Leakage current and short circuit current frequently occured an raining day