MCQ
21. স্ট্রিট লাইটের লোড ঠিক রাখার জন্য নিচের কোনট ব্যবহার করা দরকার?
কারেন্ট ট্রান্সফরমার
পটেনশিয়াল ট্রান্সফরমার
পাওয়ার ট্রান্সফরমার
কনস্ট্যান্ট কারেন্ট ট্রান্সফরমার
22. Skin effective is more in case of
communication lines
same in both cases
power lines
none of the above
23. If skin depth is more, then skin effect is--
more
less
either 1 or 2
none of the above
24. Proximity effect depends on--
frequency
distance between the conductors
relative permeability
all of the above
25. Surge impedance loading of a transmission line can be increased by-
increasing its voltage level
addition of lumped inductance in parallel
addition of lumped capacitance in series
both 1 and 3
26. If the diameter of the conductor is increased-
the inductance is increased
the inductance is decreased
the resistance is increased
no change in inductance and resistance
27. The fact that current density is higher at the surface when compared to centre is known as--
corona
proximity effect
skin effect
all of the above
28. If we increase the length of the transmission line, the charging current-
increases
decreases
remains unaffected
none of the above
29. Find the number of strands of ACSR conductor for 3-layer transmission line.
1
7
19
29
30. A transmission line has 50km operating at frequency of 500Hz. Find the type of the line.
long transmission line
short transmission line
medium transmission line.
any of the above
31. Zero voltage regulation is possible only for-
lagging power factor
unity power factor
leading power factor
all of the above
32. Which of the following transmission line is most practically used in load flow analysis?
Nominal T
Nominal II
either 1 or 2
nether1 nor 2
33. If we increase the spacing between the phase conductors, the line capacitance-
increases
decreases
remains unaffected
none of the above
34. In transmission lines distribution constants--
resistance
inductance and capacitance
inductance and resistance
both 1 and 2
35. A 3-layer and diameter of each strand is d, then find the total diameter of ACSR conductor.
2d
d
3d
5d
36. Apart from the skin effect the non-a of the current distribution is also caused by--
bundled conductors
ferranti effect
proximity effect
all of the above
37. Transmission lines are transposed to reduce-
ferranti effect
skin effect
proximity effect
all of above
38. Condition for maximum voltage regulation-
tanφ = X/R
Cosφ = X/R
tanφ = R/X
Cosφ = R/X
39. সিনক্রোনাস মোটরের জন্য কোন কথাটি সঠিক?
এটি ধ্রুব গতিতে ঘুরে
লোড পরিবর্তনে এর গতির পরিবর্তন হয়
এটি শুধু লিডিং পাওয়ার ফ্যাক্টরে চলে
এটি নিজে নিজে স্টার্ট নিতে পারে
40. Skin effect depends on-
frequency
conductivity
relative permeability
all of the above