A) Minimum
B) Maximum
C) Zero
D) None
2. At ......... frequency the parallel R-L circuit behaves as purely resistive?
A) Low
B) Very low
C) High
D) Very high
3. The power factor of a series R-L-C circuit at its half-power point is?
A) Unity
B) Lagging
C) Leading
D) Lagging (or) leading
4. A coil with large distributed capacitance has a ?
A) High resonant frequency
B) Low resonant frequency
C) Low quality factor
D) Low resistance
5. In case of two phase supply the electrical displacement of the winding is ?
A) 180
B) 120
C) 90
D) 60
6. With the increase in cross sectional area of the conductor, the value of resistance?
A) Increases
B) Remains same
C) Decrease
D) Becomes
7. With the increase in temperature, the resistance of capper ?
A) Decreases
B) Increases
C) Becomes zero
D) Remains constant
8. Specific resistance of a conductor depends upon?
A) Composition of the conductor
B) Length of conductor
C) Area of cross-section of the conductor
D) Resistance of the conductor
9. The meter which measure resistance is known as ?
A) Ammeter
B) Multi meter
C) Volt meter
D) Ohm meter
10. A current of 5A flows through a conductor against a potential difference of 200 Volts, the power dissipated will be?
A) 1000 watts
B) 1.1 kilo-watts
C) 2000 watts
D) 100 watts
11. One board of trade unit is equal to?
A) 36×106 joules
B) 36×105joules
C) 3.6×105 joules
D) 36×107joules
12. Mica condenser is a type of ?
A) Variable condenser
B) Electrolytic condenser
C) Fixed condenser
D) None of the above
13. Mica (or) ceramic condenser is a type of ?
A) Fixed condenser
B) Variable condenser
C) Electrolytic condenser
D) None of these
14. With the rise of temperature, dielectric strength of materials ?
A) Increase
B) Remain constant
C) decreases
D) Becomes zero
15. The unit of M.M.F is ?
A) Volts
B) Ergs
C) Amp-turns
D) Coulombs
16. The direction of magnetic field set up in a current carrying conductor can be found out by ?
A) Flemings right hand rules
B) Flemings left hand rules
C) Cork screw rules
D) Thumb rules
17. Q-factor of a circuit is given by?
A) Ratio of R/2
B) Ratio of Z/2
C) Ratio of XL/2
D) Ratio of XC/2
18. In a parallel resonant circuit frequency the q factor is?
A) 1/R√1/C
B) 1/R√L/C
C) 2ΠfL/R
D) CR/L
19. In a parallel resonant circuit at resonant frequency the line current is?
A) Maximum
B) Zero
C) Minimum
D) None
20. The power factor of a R-L-C circuit of which XL>XC is?
A) Lagging
B) Leading
C) Zero
D) Unity
21. The total current if the parallel circuit can be determined by?
A) Kirchhoff’s law
B) Super position theorem
C) Admittance method
D) Suspectance method
22. Horse power is the unit of ?
A) Electrical energy
B) Work
C) Power
D) Force
23. In M.K.S system one horse power is equal to?
A) 746 watts
B) 735.5 watts
C) 830 watts
D) 4180 watts
24. Three resistance of 6 ohms each are connected in parallel across 6 volts supply the total resistance of the circuit will be?
A) 18 ohms
B) 12 ohms
C) 6 ohms
D) 2 ohms
25. The unit of electrical energy is?
A) Watts
B) Kilo-watts
C) Kilo-watts-hours
D) Joules
26. The speed of a p-poles synchronous machine in R.P.M is given by?
A) 120f/P
B) 120P/f
C)√120ƒP
D) 120fP
27. Alternator are usually designed to generate?
A) Definite current
B) Definite power factor
C) Variable frequency
D) Definite frequency
28. What is the largest size of alternator being manufactured in India?
A) 500 MW
B) 250 MW
C) 209 MW
D) 190 MW
29. Two inductor with self inductance L1 and L2 .the mutual inductance between the coil is ’M’ then its coefficient of coupling (k) is given by?
A) K=ML1L2
B) K= M/√L1L2
C) K= √L1L2/M
D) L1L2
30. Inductance is defined as ?
A) Rate of change of flux
B) Rate of change of current
C) Rate of change of e.m.f
D) Change of flux linkage per ampere
31. When temperature of conductor is raised, its resistance
A) 2 joules
B) 4 joules
C) 1 joules
D) 2.5 joules
32. A 50μf capacitor is changed from a 200v supply the electrostatic energy stored in it is
A) 2 joules
B) 4 joules
C) 1 joules
D) 2.5 joule
33. The units of electric flux density is
A) Volts/meter
B) Wb/m2
C) Faraday
D) Coulomb/m2
34. Capacitive resistance is more when
A) Capacitance is less and frequency is more
B) Capacitance is more and frequency is more
C) Capacitance is less and frequency is less
D) Capacitance is more and frequency is less
35. The frequency at which a series R-L-C circuit resonant is depends on the value of
A) C and R
B)L and C
C) Rand L
D)R, L, and C
36. P=√3VLILcosφ is the power expression for 3-φ system then phase angle φ is the angle between
A) Phase voltage and line current
B) Phase voltage and phase current
C) Line voltage and phase current
D) Line voltage and line current
37. The power in a 3-phase circuit is given by
A) √3VLIL cosφ
B) VLIL cosφ
C) √3VLIL sinφ
D) 3VLIL sinφ
38. In an a.c series circuit, the inductive reactance is 20 ohms, the capacitive reactance is 60 ohms, the resistance is 30 ohms & the current is 2A, the impedance of the circuit is
A) 50 Ω
B) 25 Ω
C) 12.5 Ω
D) 8.4 Ω
39. The form factor of an a.c quantity is expressed as
A) rms value avg.value
B) rms value max.value
C) avg. value rms value
D) avg. value max.value
40. The resonant frequency fr for a R-L-C circuit is given by fr = ……Hz
A) R/2ΠL
B) C/2ΠL
C) 1/√LC
D) L/2ΠL
41. The power factor of a circuit comprising resistance R & reactance X in series is
A) R/√R2+X2
B) X/√R2+X2
C) R/R2+X2
D) X/R2+X2
42. The 3-phase, 4-wire system is also called
A) Delta
B)Star
C) Delta or Star
D) None of these
43. 3-phase, 3-wire system is also called
A) Delta
B) Star
C) Delta or Star
D)None of these
44. In star connection
A) Line voltage = Phase voltage
B) Line voltage = √3 Phase voltage
C) Line voltage = line current
D) None of these
45. In delta connection
A) Line voltage = Phase voltage
B) Line voltage =√3Phase voltage
C) Line voltage = Phase voltage
D) None of these
46. I is line voltage is VL & line current is IL & phase angle is θ, the power in the 3-θ circuit can be expressed as
A) P = VLILcosθ
B) P = V3I3cosθ
C) P = √3VLILcosθ
D) P = 3VLIL
47. In moving coil instrument the damping torque is developed by
a) Air friction
b) Eddy current damping
c) Gravity friction
d) Fluid friction damping
48 The force of acting in a M.C instrument is equal to
a) B.L.V
b) B.L.V sinθ
c) B.L.i
d) B.L.i sinθ
49. M.C type instruments are used on
a) A.C
b) D.C
c) A.C or D.C
d) None of these
50. The force which produces movement the pointer of an instrument the pointer of an instrument is called
a) Deflecting force
b) Controlling force
c) Damping force
d) Distracting force
51. What is the purpose of providing a mirror behind the pointer in a measuring instrument?
a) The scale is illuminated through the mirror
b) To observe that the pointer is behind or not
c) Being semi-transparent, a mirror helps in the study of inner construction of the instrument
d) To make the reading free from an error by removing parallax between the pointer and its image
52. When using any instrument for measurement or testing purpose, first attention should be given to the
a) Theoretical knowledge
b) Personal safety
c) Surroundings
d) Dress
53. Which one of the following statements is true about the internal resistance of an ammeter and a voltmeter?
a) The internal resistance of an ammeter should be very low and that of a voltmeter should be very high
b) The internal resistance of an ammeter be very high and that of a voltmeter should be very low
c) The internal resistance of an ammeter and voltmeter should be very low
d) The internal resistance of an ammeter and voltmeter should be very high
54. The reliability of measuring instrument means
a) Life of the instrument
b) The extent to which its characteristics remain linear
c) The degree to which repeatability continues to remain within specific limits.
d) all of these
55. The sensitivity of a measuring instrument means
a) The maximum value of a physical quantity that can be measured
b) The highest reading of the scale
c) The minimum reading of the scale
d) The smallest amount of a physical quantity that can be detected by the instrument
56. In order to increase the range of a voltmeter
a) A low resistance is connected in series
b) A low resistance is connected in parallel
c) A high resistance is connected in series
d) A high resistance is connected in parallel
