## practice set

### SSC JE ELECTRICAL PRACTICE SET - 2

1.
 Which of the following material does not allow the current to flow in it A Conductor B Insulator C Semiconductor D Superconductor Answer : B Explanation :
2.
 How much power (in W)  will be dissipated by a  5 Ohm resistor in which the value of current is  2 A A 10 B 30 C 20 D 40 Answer : C Explanation :
3.
 Which property of an electrical conductor opposes a change in the current A Resistance B Capacitance C Conductance D Inductance Answer : D Explanation :
4.
 What is the resistivity (in Ohms-m) of a  2 ohm cylindrical wire when the length and the diameter of the wire are 10 m and 0.4 m respectively A 0.025 B 0.0025 C 0.25 D 0.05 Answer : A Explanation :
5.
 Farad is the  S.I. unit of  ________ . A Inductance B Resistance C Capacitance D Reluctance Answer : C Explanation :
6.
 What is the equivalent capacitance  (in μF)  for the circuit given below A 4.56 B 4.32 C 54.65 D 54.28 Answer : B Explanation :
7.
 What will be the resistance (in Ohms)  of  a lamp rated at  220 V,  200 W A 220 B 224 C 244 D 242 Answer : B Explanation :
8.
 What is the equivalent resistance  (in Ohm)  for the circuit given below A 5 B 7 C 10 D 4 Answer : A Explanation :
9.
 Two  wires of same resistivity have equal length. The cross sectional area of first wire is two times to the area of the other. What will be the resistance  (in Ohms)  of the wire that has a large cross sectional area, if the resistance of the other wire is  20 ohms A 40 B 20 C 30 D 10 Answer : D Explanation :
10.
 What will be the resistance  (in Ohms) of bulb A for the circuit given below A 4.65 B 2.36 C 3.3 D 1.33 Answer : D Explanation :
11.
 Which of the following statement is  CORRECT A Norton’s theorem is same as superposition theorem. B Norton’s theorem is the converse of superposition theorem. C Norton’s theorem is same as Thevenin’s theorem. D Norton’s theorem is the converse of Thevenin’s theorem. Answer : D Explanation :
12.
 The algebraic sum of the electric currents meeting at a common point is  __________ A Infinity B Zero C One D Negative Answer : A Explanation :
13.
 Which of the following law is based on the conservation of energy A Kirchhoff’s  Current  Law B Kirchhoff’s  Voltage  Law C Ohm’s Law D Coulomb’s Law Answer : B Explanation :
14.
 What is the value of current  I4  (in A)  for the given junction A 4 B -4 C 6 D -6 Answer : C Explanation :
15.
 What is the value of Norton resistance (in Ohm) between the terminal  A  and  B  for the given Norton’s equivalent circuit A 2 B 4 C 4.66 D 5.6 Answer : C Explanation :
16.
 Determine the value of current  (in A)  through both the resistors of the given circuit A – 2, – 1.5 B 2, 1.5 C – 2, 1.5 D 2, – 1.5 Answer : B Explanation :
17.
 The SI  unit of magnetic flux  is  __________ A Henry B Coulomb C Tesla D Weber Answer : D Explanation :
18.
 The relative permeability of diamagnetic materials is  _________ . A Greater than 1 B Greater than 10 C Less than 1 D Less than 10 Answer : C Explanation :
19.
 Which of the following is the reciprocal of reluctance A Permeability B Susceptibility C Permeance D Reluctivity Answer : C Explanation :
20.
 Which of the following is the CORRECT  formula for permeance A $\frac{I}{H}$ B $\frac{B}{H}$ C $\frac{\phi&space;}{F_{m}}$ D $\frac{F_{m}&space;}{L}$ Answer : C Explanation :
21.
 Determine the intensity of magnetization (in A/m)  of a magnet when it has a pole strength of  60 A-m  and  a pole area of  20 sq. m A 9 B 4 C 6 D 3 Answer : D Explanation :
22.
 What will be the magnitude of induced  EMF  (in V)  in a coil that has  200 square loops, each of side  5 cm  and  placed normal to a magnetic field ? The magnetic field increases at the rate of  4  Weber per  sq. meter. A 1 B 2 C 3 D 4 Answer : B Explanation :
23.
 What will be the value of current (in A)  in a  40 cm  long solenoid in free space, if it has  400 turns,  2 cm of diameter and produces a magnetic field of 4 mT at its centre A 4.23 B 5.15 C 3.18 D 2.34 Answer : C Explanation :
24.
 What will be the self-inductance (in H)  of a 2 m long air-core solenoid, if the diameter of the solenoid is 25 cm and has  600 turns A 0.011 B 0.045 C 0.132 D 0.645 Answer : A Explanation :
25.
 What will be the mutual inductance (in mH) between the two coils. If a current of 2 sin (100 t) passes through one of the coil, which induces a maximum  EMF  of 10V  in the second coil A 40 B 20 C 50 D 60 Answer : C Explanation :
26.
 Determines the magnitude of the  EMF  (in V)  induced between the axis of rotation and the rim of the disc, when the disc of diameter  40 cm  rotates with an angular velocity of  40  revolutions per second and placed in a magnetic field of  1 T  acting parallel to the rotation of the disc A 0 B 10 C 14.14 D 17.32 Answer : C Explanation :
27.
 What is the peak value of the alternating voltage (in V)  having an average value of  180 V A 254.59 B 282.57 C 333.34 D 359.96 Answer : B Explanation :
28.
 The capacitive reactance of a circuit is  60 Ohms, when it is supplied with a  50 Hz supply. What will be the value of capacitive reactance (in Ohms) of the same circuit, if it is supplied with a 60 Hz supply A 50 B 60 C 75 D 125 Answer : A Explanation :
29.
 A parallel  RLC  circuit is being supplied by a  DC  source as shown in the figure below. What is the value of current flowing through the capacitor (in A) A 0 B 0.5 C 1 D 2 Answer : A Explanation :
30.
 Calculate the value of phase angle (in Degrees) in a series  RC  circuit having a resistance of  50 Ohms  and a capacitive reactance of  86.6 Ohms,  when supplied with a frequency of  50 Hz A 15 B 30 C 45 D 60 Answer : D Explanation :
31.
 What is the value of the total impedance (in Ohms) of a tank circuit working at resonant frequency having a capacitance of  0.01 mF and an inductance of  0.01 mH A 0 B 10 C 100 D ∞ Answer : D Explanation :
32.
 Calculate the time (in seconds) taken by a series  RL  circuit having inductance of  0.6 H  and resistance of  30 Ohms  to each a steady state value A 0.02 B 0.05 C 0.1 D 0.5 Answer : C Explanation :
33.
 Which of the following is  NOT  correct about a star connected balanced  3-phase  circuit A The phase current is equal to the line current. B The phase voltage is less than the line voltage. C The system does not contain a neutral point. D It is a four wire system. Answer : C Explanation :
34.
 A 3-phase delta connected system is supplied by a line voltage of  400 V. the value of phase current is  70 A. what is the power (in kW) consumed by the system, if the current lags the voltage by  60 degrees A 16.8 B 42 C 67.2 D 84 Answer : B Explanation :
35.
 What is the apparent power of a  3-phase star connected system having a line voltage of  250 V  and a line current of  40 A  and the phase difference between the voltage and current is  36.87 degrees A 13.856 kW B 13.856 kVA C 17.32 kW D 17.32  kVA Answer : D Explanation :
36.
 Which of the following is the dimension of resistance A $\frac{ML^{2}}{Q^{2}T}$ B $\frac{Q^{2}T^{2}}{ML^{2}}$ C $\frac{ML^{2}}{QT^{2}}$ D $\frac{ML}{QT^{2}}$ Answer : A Explanation :
37.
 A factory runs in  3  shifts of  8 hours each, in which it consumes  30 kW,  15 kW  and 25 kW  in each shift respectively. calculate the energy (in kWh) consumed by the factory per day A 186.67 B 373 C 560 D 746.67 Answer : C Explanation :
38.
 In  2  wattmeter method of power Calculation of a 3-phase balanced star connected system, what is the power factor of the system if one of the wattmeter shows zero reading and the other shows a positive reading A 0 B Greater than  0  but less than  0.5 C 0.5 D Greater than  005  but less than  1 Answer : C Explanation :
39.
 Which of the following is  NOT  an advantage of  PMMC  type instruments A Frictional error is low B Single instrument can be used for multi range measurements of voltage and current C Uniformly divided scale. D Stray magnetic field error is small Answer : D Explanation :
40.
 Which of the following quantities cannot be measured using a multi-meter A AC voltage B DC current C Phase Angle D Resistance Answer : C Explanation :
41.
 Which of the following can measure the resistance having value below  1 Ohms  most precisely A Kelvin’s Double Bridge B Megger C Multi-meter D Wheatstone Bridge Answer : A Explanation :
42.
 Which of the following materials when used as the viewing surface of a  CRO  given a bluish glow A Zinc Sulphide with copper as impurity B Zinc Sulphide with silver as impurity C Yttrium Oxide D Pure Zinc Sulphide Answer : A Explanation :
43.
 What is the percentage voltage error of a potential transformer with system voltage of  11,000 V  and having turns ratio of  100, if the measured secondary side voltage is  105 V A 2.75 B 3.55 C 4.54 D 9.09 Answer : C Explanation :
44.
 Which of the following is the cause of a speed error in induction type energy meter A Incorrect position of brake magnets. B Incorrect adjustment of the position of shading bands. C Slow but continuous rotation of aluminium disc. D Temperature variations Answer : A Explanation :
45.
 A circuit having power factor of  0.8 consumes 20 W. what is the value of reactive power (in VAR) of the circuit A 10 B 15 C 20 D 25 Answer : B Explanation :
46.
 During plugging, external resistance is also introduced into a circuit to limit the flowing  _________ . A Current B Voltage C Current and voltage both D None of these Answer : A Explanation :
47.
 A Transformer A Changes  AC to DC B Changes  DC to AC C Steps  up or down  DC Voltages  &  Current. D Steps  up or down  AC Voltages  &  Current. Answer : D Explanation :
48.
 The overall power factor of an On-load transformer  ________ . A Depends on the power factor of the load. B Is always lagging. C Is always unity. D Is always leading Answer : A Explanation :
49.
 Dynamic braking can be used for which of the following A Shunt motors B Series motors C Compound motors D All options are correct Answer : D Explanation :
50.
 The parts of the armature electric circuit which take active part in emf generation are  ________ A The coil sides inside the slots B The overhangs C Both The coil sides inside the slots and The overhangs D The commutator segments Answer : A Explanation :
51.
 The inter-poles in dc machines have a tapering shape in order to A Reduce the overall weight B Reduce the saturation in the inter-pole C Economise on the material required for inter-poles D Increase the acceleration commutation Answer : B Explanation :
52.
 Maximum efficiency will occur, when copper loss and iron loss are A Unity B Zero C Unequal D Equal Answer : D Explanation :
53.
 The higher the voltage in the transmission line, the current which flow through the transmission line for a given power to be transmitted will be A Higher B Equal C Lower D Unity Answer : C Explanation :
54.
 No-load test on induction motor is conducted to find which of the following losses A Stator core loss B Rotational  loss C Stator copper loss D All options are correct Answer : D Explanation :
55.
 If the torque of the induction motor decreases, the  _________ A Speed of rotor increases B Speed of rotor decreases C Current of the rotor decreases D Power of the motor decreases Answer : A Explanation :
56.
 Reduction in the capacitance of a capacitor-start motor results in reduced  ________. A Noise B Speed C Starting torque D Armature reaction Answer : C Explanation :
57.
 A single-phase induction motor with only the main winding excited would exhibit the following response at synchronous speed A Rotor current is zero B Rotor current is non-zero is at slip frequency C Forward and backward rotating fields are equal D Forward rotating field is more than the backward rotating field Answer : D Explanation :
58.
 The electric motor used in portable drills is  ________ . A Capacitor run motor B Hysteresis motor C Universal motor D Repulsion motor Answer : C Explanation :
59.
 In which single-phase motor, the rotor has no teeth or winding A Split phase motor B Reluctance motor C Hysteresis motor D Universal motor Answer : C Explanation :
60.
 The range of efficiency for shaded pole motors is A 95%  to  99% B 80%  to  90% C 50%  to  75% D 5%  to  35% Answer : D Explanation :
61.
 The direction of rotation of universal motor can be reversed by reversing the flow of current through  __________ A Armature winding B Field winding C Either Armature winding or  Field winding D None of these Answer : C Explanation :
62.
 Which of the following statement is  incorrect A As the temperature rises, the tension in the transmission line decreases B As temperature rises, the sag in transmission line reduces C Tension and sag in transmission lines are complementary to each other D None of these Answer : B Explanation :
63.
 Series capacitors in transmission lines are of little use when A The load  VAR  requirement is small B The load  VAR  requirement is large C The load  VAR  requirement is fluctuating D None of these Answer : A Explanation :
64.
 Stability of a system is not affected by  ________ . A Reactance of line B Losses C Reactance of generator D Output torque Answer : B Explanation :
65.
 Which of the following is not a constituent for making porcelain insulators A Silica B Kaolin C Feldspar D Quartz Answer : A Explanation :
66.
 Name the generating station where electrical energy is generated through steam A Thermal power station B Diesel power station C Hydro power station D Nuclear power station Answer : A Explanation :
67.
 In a 3-phase 4-wire cable, the cross-sectional area of neutral conductor is A Equal to phase conductor B More than phase conductor C Half the phase conductor D None of these Answer : C Explanation :
68.
 Fuse is always made up of alloys and metals having A High resistance and high melting points B High resistance and Low melting points C Low resistance and Low melting points D Low resistance and High melting points Answer : C Explanation :
69.
 In case of stair case wiring which type of switch is used A 2 one way switches B 1 one way switch C 2 two way switch D 1 two way switch Answer : C Explanation :
70.
 Two incandescent lamps of wattage 40W, 60W are connected in series with voltage of  230 V. which out of the two lamps will glow brighter A 40 W B 60 W C Both brightly D Both dim Answer : A Explanation :
71.
 Rating of fuse wire is expressed in terms of  ________ . A Ohms B Mhos C Amperes D Watts Answer : C Explanation :
72.
 A 3-phase, 4-wire system is commonly used on  ________ A Primary transmission B Secondary transmission C Primary distribution D Secondary distribution Answer : D Explanation :
73.
 Insulator that is used in low voltage distribution lines is known as  ________ A Shackle B Strain C Pin D Suspension Answer : A Explanation :
74.
 Which of the following type of lamp gives more illumination from low wattage A Incandescent lamp B Fluorescent lamp C Compact Fluorescent lamp D LED  lamp Answer : D Explanation :
75.
 The fuse is installed in which of the following wire A Neutral B Phase C Earth D All options are correct Answer : B Explanation :
76.
 The wave form of the armature m.m.f. in  DC  machine is  ________ . A Square B Rectangular C Triangular D Sinusoidal Answer : C Explanation :
77.
 Light waves travel  with a velocity of  _________ A 3 × 1010 cm/s B 3 × 1012 cm/s C 3 × 1015 cm/s D 3 × 1018 cm/s Answer : A Explanation :
78.
 Light is produced in electric discharge lamps by  _________ A Heating effect of current B Magnetic effect of current C Ionisation in a gas or vapour D Carbon electrodes Answer : C Explanation :
79.
 A  DC  generator can be termed as  _________ A Rotating amplifier B Prime mover C Power pump D None of these Answer : A Explanation :
80.
 Which of the following has the highest value of thermal conductivity A Aluminium B Brass C Copper D Iron Answer : C Explanation :
81.
 During resistance welding heat produced at the joint is proportional to  _________ A Current B Voltage C I2 R D Volt-amperes Answer : C Explanation :
82.
 Which of the following is tetravalent A Quartz B Diamond C Germanium D Antimony Answer : C Explanation :
83.
 The acceptor type of impurity is  _________ . A Phosphorous B Aluminium C Boron D Iron Answer : C Explanation :
84.
 The reverse bias characteristics of a semiconductor diode is shown in Figure Figure Figure Figure A I B II C III D IV Answer : B Explanation :
85.
 The peak inverse voltage, in case of a bridge rectifier, for each, diode is  :  (where,  Em  =  peak value of input voltage) A Em  . B 2Em  . C 3Em  . D 4Em  . Answer : A Explanation :
86.
 In an electronic circuit transistor is used for switching  ON  and  OFF  a relay, when the transistor switches  OFF  the relay, a higher voltage appears across the transistor. How can a transistor be protected from this voltage A A capacitor in series to the relay B A resistor in series to the relay C An inductor parallel to the relay D A diode parallel to the relay Answer : D Explanation :
87.
 The efficiency of the class  B  amplifier is approximately A 10%  to  30% B 30%  to  50% C 50%  to  60% D 70%  to  100% Answer : D Explanation :
88.
 The oscillations in a synchronous motor can be damped out by A Maintaining constant excitation B Providing damper bars in the rotor pole faces C Running the motor on leading power factors D Oscillations cannot be damped Answer : B Explanation :
89.
 An over excited synchronous motor is used for  _________ . A Variable speed loads B Low torque loads C Power factor corrections D High torque loads Answer : C Explanation :
90.
 Synchronous motors are  ________ . A Essentially self-starting B Not-self starting C Self-starting D None of these Answer : B Explanation :
91.
 The  under-excited synchronous motor takes  ________ . A Leading  current B Lagging current C Both Leading  current and Lagging current D None of these Answer : B Explanation :