DFCCIL Recruitment 2021
Dedicated Freight Corridor Corporation of India Limited (DFCCIL) Public Sector Undertaking under the administrative control of the Government of India (Ministry of Railways).DFCCIL has released the official notification for the recruitment of 1074 vacancies for the recruitment of Junior Executives, Executives, and Junior Managers through their official website, i.e. dfccil.com.
EXAM DATES
26 SEPT TO 30 SEPT
DFCCIL’21 EE: Daily Practices Quiz
DFCCIL’21 EE: Daily Practices Quiz 22-Sep-2021
Each question carries 1 mark.
Negative marking: 1/4 mark
Total Questions: 06
Time: 08 min.
Q1. A XOR gate produces an output only when its two inputs are
(a) Same
(b) Low
(c) High
(d) Different
Q2. In a P-pole, f-Hz, 3-phase induction motor, synchronous angular velocity in mechanical and electrical radians per second is respectively?
(a) 4πf/P,2πf/P
(b) 2πf/P,4πf/P
(c) 2πf/P,4πf
(d) 4πf/P,2πf
Q3. A stepper motor has a step angle of 2.5⁰. If the shaft is to make 25 revolutions, the number of steps required will be:
(a) 1800
(b) 3600
(c) 2200
(d) 2800
Q4. Transfer function is defined for:
(a) linear system only
(b) non-linear system only
(c) Linear time-invariant system only
(d) Linear time-dependent systems only
Q5. A second order control system has a transfer function 16/(s^2+4s+16). Find the settling time for 2% tolerance?
(a) 2 sec.
(b) 5 sec.
(c) 10 sec.
(d) 20 sec.
Q6. The line integral of magnetic field intensity around closed path is equal to current enclosed by path.” This Statement is associated with which law?
(a) Coulomb’s law
(b) Gauss’s law
(c) Ampere’s circuital law
(d) Lenz’s law
SOLUTIONS
S3. Ans.(b)
Sol. Number of revolutions=25
Angle rotated(Ө)=25×360⁰
Number of steps=(25×360^0)/2.5^0 =3600.
S4. Ans.(c)
Sol. Transfer function = (Laplace of O\/p)/(Laplace of i\/p)
→ with initial condition zero.
→ applicable for linear TIV system.
S5. Ans.(a)
Sol. For given transfer function, _n=4 rad/s
ξ=damping ratio=0.5.
So, for 2% tolerance, settling time=4/(ξωn )=4/(0.5×4)=4/2=2 sec.