Mcqs for rrb je electrical engineering

RRB Junior engineer(electrical) Model Questions
1. A resistance of 10 ohm is connected across a supply of 200V. If resistance R is now connected in parallel with a 10 ohm resistance, the current drawn from the supply gets doubled. The value of unknown resistance R is
(a) 5 ohm
(b) 20 ohm
(c) 10 ohm
(d) 15 ohm
Ans : c
2. Kirchhoff’s first law is also called as
(a) voltage law
(b) Current law
(c) Mesh Current law
(d) All the above
Ans : b
3. Find the total resistance when four 3 Ohm resistance are connected in series
(a) 3 ohm
(b) 12 ohm
(c) 14 ohm
(d) 8 ohm
Ans : b
4. The practical unit of power is
(a) Joule
(b) Ampere
(c) Watt
(d) Weber
Ans : c
5. Form factor of a sine wave is
(a) 1.414
(b) 1
(c) 0
(d) 1.11
Ans : d
6. The unit of resistance is
(a) Mho
(b) ohm-m
(c) Ohms
(d) Amps
Ans :c
7. Unit of impedance is
(a) Ampere
(b) Volt
(c) Ohm
(d) mho
Ans : c
8. The close path of the flux around any current carrying circuit is referred as
Circuit.
(a) Magnetic
(b) Electric
(c) Electromagnetic
(d) None of these
Ans : a
9. The current flowing in an electrical circuit is due to the existence of
(a) mmf
(b) emf
(c) Resistance
(d) Reluctance
Ans : b
10. The magnetic flux flow through a magnetic circuit is due to
(a) mmf
(b) emf
(c) Resistance
(d) Reluctance
Ans : a
11. The on-line UPS is also called as
a. Stand-by UPS
b. Line Interactive UPS
c. Off line UPS
d. Current line UPS
Ans. b
12. ____ is used to convert alternating current to direct current.
a. Transformer
b. Diode
c. Resistor
d. Transistor
Ans. b
13. The supply voltage varies sinusoid ally and has a frequency ______ Hz.
a. 60
b. 50
c. 20
d. 10
Ans. b
14. Expression for magneto-motive force is
(a) N/I
(b) 1/NI
(c) I/N
(d) IN
Ans : d
15. Unit of mmf is
(a) Ampere /Volt
(b) Ampere- turns
(c) Volt
(d) Volt/Ampere
Ans : b
16. Magnetic field strength is equal to
(a) mmf. L
(b) L/ mmf
(c) mmf/ L
(d) 1/mmf.L
Ans : c
17. Peak inverse voltage of bridge rectifier is as that of centre-tap circuit.
a. Same
b. Twice
c. Half
d. Four times
Ans. c
18. Peak Resistance of the diode is increased when
a. Forward biased
b. Reverse biased
c. Both forward and reverse biased
d. Either a or b
Ans. b
19. The number of lines of force passing through the secondary coil S when unit current changes in the primary coil P are called
(a) Self inductance
(b) Mutual inductance
(c) Self induction
(d) Mutual induction
Ans : c
20. Unit of flux
(a) Amp- turns
(b) Weber
(c) Volts
(d) Amps
Ans : b

ELECTRONICS AND COMMUNICAN ENGINEERING (ECE) 220 OBJECTIVE QUESTIONS AND ANSWER IN ONE PDF

1.  Of  the  following  bridges  the  one  which  can  be  used  for  the  measurement  of  dielectric  loss  of  a capacitor  is
   a.)  Schering  bridge
   b.)  Heaviside  campbell  equal  ratio                     voltage
  c.)  Owen  bridge
  d.)  Anderson  bridge
 Ans.  a.)  Schering  bridge

 2.  LBDT  is  uses  as  a  ?
a)  .  Displacement  transducer
b.)  Pressure  transducer
c.)  Temperature
d.)  Any  of  the  above
Ans.  a).  Displacement  transducer

3.  Polarization  is  a  measure  of  -
a.)  Dielectric  constant  per  unit  volume. b.  )  Voltage  gradient  to  produce  electrical  breakdown
c.)  Product  of  charge  and  distance
d.)  Excess  charge  density
Ans.  a.)  Dielectric  constant  per  unit  volume

4.  Compared  to  the  inductive  type  of  transducer,  capacitive  transducer  is  superior  for  the measurement  of  displacement  because  of  -
a.)  Absence  of  non-linearity
b.)  High  frequency  response
c.)  Small  size
d.)  High  accuracy
Ans.  b.)  High  frequency  response

5.  An  incremental  model  of  a  solid  state  device  is  one  which  represents  the  ?
a.)  ac  property  of  the  device  at  the  desired  operating  point
b.  )  dc  property  of  the  device  at  all  operating  points
c.)  Complete  ac  and  dc  behaviour  of  the  device  at  all  operating  points
d.)  ac  property  of  the  device  at  all  operating  points.
Ans.  a.)  ac  property  of  the  device  at  the  desired  operating  point