MCQ
3781. In D.C motors diverters are used in-
Cumulative compound motors
Differentially compound motors
Shunt motors
Series motors
3782. The starting resistance of DC motor is generally-
High
Infinite
Low
None of the above
3783. In a DC shunt motor if field current is decreased then the speed of the motor is-
Decrease
Increase
Remain same
None of the above
3784. A 4 pole de shunt generator with a shunt field resistance of 100 ohm and armature resistance of 1 ohm has 378 wave connected conductors in its armature. The flux per pole is 0.02Wb. If a load resistance of 10 ohm connected across the armature terminals and the generator is driven at 1000 rpm then power absorbed by the load is-
6321W
4315W
5153W
2314W
3785. নিচের কোনটি ইনপুট ডিভাইস নয়?
কী-বোর্ড
মাউস
স্ক্যানার
প্রিন্টার
3786. When the speed of the DCtor increases its Armature current-
Increases
Decreases
Remain constant
Any of the above
3787. For highly explosive atmosphere which of the following motor is generally preferred?
Battery operated motor
Series motor
Air mesur
Shunt motor
3788. When the speed of DC motor is increased-
Back E.M.F increases and current drawn decreases
Back E.M.F decreases and current drawn increases
Back E.M.F and current drawn both increases
Back E.M.F and current drawn both decreases
3789. ১ টেরা সমান --- গিগাবইট?
১২০০
১১০০
১০০০
২১০০
3790. The function of yoke in a DC machine is-
To provide mechanical protection
To reduce eddy current
Flux path completion
Both a & c
3791. When the ratio of back EMF to applied voltage is -- then the mechanical power developed by the shunt generator is maximum.
1.0
0.5
2
3
3792. What will happen if the 220 volts DC series motor is connected to 220 Volt AC supply?
The motor will not run
The armature winding of the motor will burn
The motor will run with less efficiency and more sparking
Either b & c
3793. . A 250V, DC shunt motor takes a line current of 20A. Resistance of shunt field winding is 2002 and resistance of the armature is 0.30. Find the armature current and the back e.m.f.
18.75A, 244V
25.32A, 225V
15.65A, 100V
10A, 150V
3794. In DC motor the percentage of residual magnetism is
2-3%
10-20%
50%
80-90%
3795. The amount of back emf of a shunt motor will Increase when
the load is increased
the field is weakened
the field is strengthed
None of the above
3796. The function of dummy coil is to-
Reduce eddy current
Reduce hysteresis loss
Increase flux
Mechanical balancing
3797. Digital Coding Technique কোনটি?
PCM
DM
DPCM
সবগুলো
3798. নিচের কোনটি কম্পিউটারের একটি মার্কআপ ভাষা?
HTML
PHP
JAVA
PYTHON
3799. The flux density under trailing pole tip in DC motor tends to-
Decrease
Remain same
Increase
None of the above
3800. The flux density under leading pole tip in DC motor tends to -
Decrease
Remain same
Increas
None of the abovee