MCQ
2541. The current in armature conductors of a de machine is
pure de
pulsating de
ac
pure de + pulsating de
2542. Shunt are generally made of-
copper
aluminium
silver
manganin
2543. The ideal de generator is one that has ---voltage regulation
low
zero
negative
positive
2544. Which of the following quantity maintains the same direction whether a de machine runs as a generator or as a motor?
Induced emf
Armature current
Field current
Supply current
2545. The emf of a cell does not depend upon
nature of electrolyte
concentration of electrolyte
nature of material of electrodes
size and spacing of electrode
2546. The demand for a large increase in torque of a de series motor is met by a-
large decrease in current
large decrease in speed
large increase in speed
large increase in speed
2547. The term ampere-hour (Ah) is associated with-
rectifiers
transformer
electromagnets
storage cells
2548. ডিসি সিরিজ মোটর ট্রাকশন কাজের উপযোগী, কারণ-
চালুর মুহূর্তে উচ্চমানের টর্ক সৃষ্টি হয়
গতি নিয়ন্ত্রণ সহজ উপায় সম্ভব
দ্বিগুণ অতিরিক্ত লোড পর্যন্ত কমুটেশনের কাজ সুষ্ঠুভাবে সাধিত হয়
উপরি-উক্ত সব ক'টি
2549. Copper when alloyed with zinc is known as-
Brass
Bronze
Babbits
All of the above
2550. The induction motor is preferred to DC motor because it-
provides high-starting torque
provide fine speed control
has simple and rugged construction
none of the above
2551. The greatest heat loss in a de machine is due to loss.
eddy current
hysteresis
copper
friction
2552. A de motor is still used in industrial application because it
is cheap
is simple in construction
provides tine speed control
none of the above
2553. A de motor can be looked upon as de generator with the power flow-
Reduced
reversed
increased
modified
2554. একটি তিন ফেজ ইন্ডাকশন মোটর কোন ধরনের ম্যাগনেটিক ফিল্ড উৎপন্ন করে?
স্টেডি
অল্টারনেটিং
রোটেটিং
কোনোটিই নয়
2555. What is a battery?
Current source
Voltage source
Power source
None
2556. The shunt generator gives its greatest voltage at
no load
full load
half-load
quarter load
2557. pole de machines are most common.
2
4
6
8
2558. Motors used in high-speed applications have-
high torque with high speed
low torque with high speed
high torque with low speed
none of the above
2559. The armature of a de machine is laminated in order to reduce-
eddy current loss.
hysteresis loss
copper loss
friction loss
2560. The direction of a rotation of a de motor can be determined by
Lenz's law
Fleming's left-hand rule
Fleming's right-hand rule
Ampere's law