## practice set

### SSC JE ELECTRICAL PRACTICE SET - 5

1.
 Potential difference is measured in  __________ A Watt B Joule C Volts D Ampere Answer : C Explanation :
2.
 Which of the following statement is  TRUE  about the resistance of a conductor A Resistance of a conductor does not depend upon the length B Resistance of a conductor does not depend upon the material C Resistance of a conductor does not depend upon the temperature D Resistance of a conductor does not depend upon the pressure Answer : D Explanation :
3.
 In series combination of resistance, the current through each resistance is  __________ A Higher in largest resistance B Lower in largest resistance C Same in each resistance D Higher in smaller resistance Answer : C Explanation :
4.
 Siemens is the  S.I. unit of  __________ A Resistance B Conductance C Capacitance D Inductance Answer : B Explanation :
5.
 Determine the conductance (in Mho) of a conductor, when the value of current that flows through the conductor is  2 A  and the potential difference between the ends of the conductor is  40 V A 0.04 B 0.05 C 0.62 D 0.24 Answer : B Explanation :
6.
 What will be the value of equivalent capacitance, if three capacitors having capacitance  C  are connected in series A 3 C B C/3 C 6 C D C/6 Answer : B Explanation :
7.
 Determine the resistance(in ohms) of a  14 m  long circuit wire when the diameter and the conductivity of the wire are  0.6 m and 12 mho/metre respectively A 1.79 B 2.84 C 3.64 D 4.17 Answer : D Explanation :
8.
 What will be the color-coding of a resistor when the resistance of the resistor is  50 + 2% ohms A Green-Black-Brown-Red B Green-Black-Black-Brown C Yellow-Brown-Black-Red D Green-Black-Black-Red Answer : B Explanation :
9.
 What will be the value of current (in A) drawn from a 4 V battery when a wire of 20 ohms resistance is stretched to double its original length and then cut into two equal parts and these equal parts are connected in parallel with the battery A 2 B 4 C 0.2 D 0.4 Answer : C Explanation :
10.
 Determine the heat dissipated (in Joule) through a conductor of 10 ohms resistance, when  1 A  of current is flowing through the conductor for  5 seconds A 50 B 40 C 20 D 60 Answer : A Explanation :
11.
 Which one of the following statement is  TRUE  about Kirchhoff’s current law A The sum of currents entering a node is greater than the sum of currents leaving the node B The sum of currents entering a node is smaller than the sum of currents leaving the node C The sum of currents entering a node is  equal  to the sum of currents leaving the node D The sum of currents entering a node is twice  the sum of currents leaving the node Answer : C Explanation :
12.
 Tellegen’s theorem is based on the principle of law of  _________ A Conservation of charge B Conservation of mass C Conservation of velocity D Conservation of energy Answer : D Explanation :
13.
 What will be the potential difference (in V) between the terminals of the resistor of  8 ohms, when the current through the resistor is  3 A A 247 B 22 C 36 D 30 Answer : A Explanation :
14.
 Which one of the following expression is the expression of maximum power theorem A $P_{max}=&space;\frac{V_{Th}}{R_{Th}}$ B $P_{max}=&space;\frac{V_{Th^{2}}}{2R_{Th}}$ C $P_{max}=&space;\frac{V_{Th^{2}}}{R_{L}}$ D $P_{max}=&space;\frac{V_{Th^{2}}}{4R_{L}}$ Answer : D Explanation :
15.
 Determine the value of source impedance  (in Ohms) for transmitting maximum power to the load in the circuit given below A 7 + j3 B 7 – j3 C 3 + j7 D 3 – j7 Answer : B Explanation :
16.
 Determine the voltage (in V) between point A and B for the given electrical circuit  Figure A 40 B 20 C 60 D 30 Answer : B Explanation :
17.
 What will be Norton’s resistance (in ohms) between terminals A and B for the given electrical circuit  Figure A 18 B 12 C 9 D 6 Answer : C Explanation :
18.
 What will the maximum power (in W) transferred from the source to the load to the circuit given below Figure A 40 B 20 C 30 D 50 Answer : A Explanation :
19.
 Determine the total power delivered (in W) by the voltage source in the circuit given below Figure A 264 B 246 C 268 D 288 Answer : D Explanation :
20.
 What will be the value of current (in A)  through R3 resistor, if a source of 3 V  with internal resistance  3Ω is connected at  P-Q terminals with positive terminal at  P  Figure A 1.2 B 1.6 C 2.2 D 2.6 Answer : B Explanation :
21.
 Which one of the following is the  CORRECT  expression for Biot-Savart law A $\phi&space;B.dl=&space;\mu&space;_{0}\Sigma&space;1$ B $\Phi&space;_{E}=&space;\frac{q}{\varepsilon&space;_{0}}$ C $dB&space;\alpha&space;\frac{idl\sin&space;\theta&space;}{r^{2}}$ D $dB=&space;\frac{ir^{2}\sin&space;\theta&space;}{dl}$ Answer : B Explanation :
22.
 Which of the following statement is  TRUE  about the magnetic lines of force A The magnetic lines of force travel from South pole to North pole outside the magnet B The magnetic lines of force travel from North pole to South pole inside the magnet C Magnetic lines of force never form a closed path D Two magnetic lines of force do not cut each other Answer : D Explanation :
23.
 Which of the following material is considered as a non-magnetic material A Diamagnetic material B Ferromagnetic material C Ferrimagnetic material D Anti-ferrimagnetic Answer : A Explanation :
24.
 Determine the current through a coil (in A), if the coil has  140 turns and produces mmf of  14 Amp-turns A 0.3 B 0.4 C 0.6 D 0.1 Answer : D Explanation :
25.
 On which of the following parameters the eddy current loss occurring in a material does not depend A Magnetic flux Density B Frequency of variation of flux C Susceptibility D Volume of the material Answer : C Explanation :
26.
 Determine the flux (in Wb) through a coil when the reluctance of the coil is  4 Amp-turns/Wb and the produced mmf is  48 Amp-turns A 10 B 12 C 14 D 16 Answer : B Explanation :
27.
 Determine the magnetic field strength (in A/m) of a material when the intensity of magnetization of the material is  0.084 Amp/m and the magnetic susceptibility of the material is  0.0012 A 70 B 700 C 0.7 D 0.07 Answer : A Explanation :
28.
 Determine the coupling factor between two coils each having self-inductance of  40 mH and the mutual inductance between them is  40 mH A 2 B 0.5 C 1 D 0.75 Answer : C Explanation :
29.
 Determine the eddy current loss (in W)  in a material having eddy current coefficient of  1, thickness of  0.03 m  and volume of  2 cubic metre which is kept in a magnetic field of maximum flux density of  3 T  and supplied by a frequency of  50 Hz A 35.5 B 30.5 C 2505 D 40.5 Answer : D Explanation :
30.
 Determine the magnitude of magnetic field  (in mT)  at the centre of a  50  cm  long solenoid, if the solenoid has  300 turns  and  carrying a current of  5 A A 2.61 B 2.66 C 4.64 D 3.77 Answer : D Explanation :
31.
 What is the total impedance (in Ohms) of the series  RLC  circuit containing resistance of 8 Ohms,  capacitive reactance of  2 Ohms and inductive reactance of  8 Ohms connected in series  across a  100 V,  50 Hz  supply A 10 B 18 C 14 D 8 Answer : A Explanation :
32.
 What is the rms value of the alternating voltage (in V)  having a peak value of  1000 V A 1414 B 707 C 141.4 D 70.777 Answer : D Explanation :
33.
 Calculate the quality factor of the resonant series  RLC circuit, if its bandwidth is  30 Hz A 30 B 15 C 2/30 D 1/30 Answer : A Explanation :
34.
 The line current for a balanced delta connected system is 10 A. calculate the value of phase current (in A) A 10 B 17.32 C 5.77 D 11 Answer : C Explanation :
35.
 For the circuit shown below, the voltage (in V) across  4mF capacitor is  _________  Figure A 37.3 B 3.73 C 0.373 D 37 Answer : B Explanation :
36.
 The maximum voltage induced in the coil is 200 V and the rotation angle of the coil is  45 degrees with respect to the coil. Find the instantaneous value of the sinusoidal waveform produced A 200 sin 450 B 200 cos 450 C $\frac{200}{\sqrt{2}}sin&space;45^{0}$ D $\frac{200}{\sqrt{2}}cos&space;45^{0}$ Answer : A Explanation :
37.
 For a pure sinusoidal waveform the form factor and crest factor are  _________  and  _________  respectively A 1.414,  1.11 B 1.11,   1.414 C 11.1,   14.14 D 14.14,   11.1 Answer : B Explanation :
38.
 A sinusoidal voltage applied across a series  R-C  circuit is given by  40 sinV. The current flowing in the circuit is  20 sin()A. determine the value of average power (in W) A 282.84 B 286.64 C 288.04 D 292.24 Answer : A Explanation :
39.
 A constant voltage of  60 V  is applied at  t = 0  across a series  R-L circuit as shown in the figure. Determine the current (in A) in the circuit at  t = 0 + Figure A 4 B 3 C 0 D 2 Answer : C Explanation :
40.
 Determine the value of inductor (in mH) connected in parallel with a capacitance of 5 F having a quality factor 6.  Assume the resonant frequency of  5 rad/s A 8 B 7 C 9 D 8.5 Answer : A Explanation :
41.
 Wien’s bridge is used to measure  _________ A Power B Energy C Phase angle D Frequency Answer : D Explanation :
42.
 Ammeter and voltmeter are connected across the load in  _________  and  _________  respectively A Series,   parallel B Parallel,   series C Series,   series D Parallel,   parallel Answer : A Explanation :
43.
 The deflection sensitivity of the  CRO  is  10 m/V. what is the value of deflection factor  (in V/m) A 10 B 0.1 C 1 D 0.01 Answer : B Explanation :
44.
 The current required for full scale deflection of a voltmeter is  10 mA. Find the sensitivity (in ohms/V) of the voltmeter A 100 B 10 C 0.01 D 0.001 Answer : A Explanation :
45.
 Calculate the fastest rise time (in ms) a sine wave can have to be reproduced by a  CRO, if the bandwidth ranges from  0 Hz to 10 Hz A 17.5 B 0.35 C 35 D 1.75 Answer : C Explanation :
46.
 Which of the following is  NOT  the correct representation of the balanced condition of  AC  bridges A l1 = l3,  l2  =  l4 B |Z1| + |Z4| = |Z2| + |Z3| C θ1 +  θ4  =  θ2 + θ3 D |Z1| |Z4|  =  |Z2| |Z3| Answer : B Explanation :
47.
 A 10 mA meter having an internal resistance of  100 ohms  is to be converted to 0-200 mA ammeter. What value of shunt resistance (in ohms) is required A 5.26 B 5 C 10.52 D 10 Answer : A Explanation :
48.
 A  3-phase – 110 V motor has a power  factor of  0.5.  The two watt-meters connected measure the total input of 50 kW. Calculate the reading (in kW)  of each watt-meter A 0, 150 B 100, 50 C 0, 50 D 50, 50 Answer : C Explanation :
49.
 The inductance of a moving iron instrument is  (10 +6θ) μH, where  θ  is the deflection in radian from zero position. Assuming spring constant  k  =  10 × 10- 6 Nm/rad,  the deflection (in rad) for a current of  6 A is  _________ A 10.8 B 10 C 9.8 D 9 Answer : A Explanation :
50.
 What will happen to the operating torque of moving iron instrument, if current through the operating coil is halved A Halved B Doubled C Remain same D One-fourth Answer : D Explanation :
51.
 Which of the following generators are used in arc welding A Shunt generators B Series generators C Cumulative compound generators D Differential compound generators Answer : D Explanation :
52.
 Calculate the force experienced by the conductor, with  L = 0.5 m  and  B  =  4 Wb/m2,  when the armature current  is  5 Amp A 5 N B 10 N C 15 N D 20 N Answer : B Explanation :
53.
 Maximum power will be developed when back emf is A Equals to supply voltage B Half to supply voltage C Doubles to supply voltage D All option are correct Answer : B Explanation :
54.
 No load saturation characteristics are plotted between A No load voltage and field current B No load voltage and armature current C Short circuit current and field current D Short circuit current and armature current Answer : A Explanation :
55.
 Transformer oil is used as A An insulator B A coolant C Both insulator  &  coolant D Inert medium Answer : C Explanation :
56.
 Which is to be short circuited on performing short circuit test on a transformer A Low voltage side B High voltage side C Primary side D Secondary side Answer : A Explanation :
57.
 A single phase  50 Hz transformer has high voltage and low voltage windings of  2200/220  V.  What is the Transformation ratio A 10 B 1/10 C 1 D None of these Answer : B Explanation :
58.
 If the air gap in an induction motor is increased   __________ A Speed of rotor increases B The power factor will decrease C The windage losses will increase D Current drawn by the motor increase Answer : B Explanation :
59.
 In three phase induction motor reversing the supply in two of the phases is called as  _________ A Pole changing B Plugging C Increase the torque D To control current Answer : B Explanation :
60.
 The drive motor used in a mixer-grinder is a A DC motor B Induction motor C Synchronous motor D Universal motor Answer : D Explanation :
61.
 The capacitors used in single-phase capacitor motors have no A Voltage rating B Dielectric medium C Polarity marking D Definite value Answer : C Explanation :
62.
 How will the total capacitance change, when two capacitors are connected in parallel A The total capacitance increases B The total capacitance decreases C The mean value gives the new capacitance D The total capacitance is found by reciprocal equation Answer : A Explanation :
63.
 A universal motor can run on A A. C. only B D. C. only C Either A. C.  or  D. C. D None of these Answer : C Explanation :
64.
 In high voltage transmission lines, the topmost conductor is A R-phase conductor B Y-phase conductor C B-phase conductor D Earth conductor Answer : D Explanation :
65.
 Different types of line supports used for transmission lines include A RCC  and  PCC  poles B Steel towers C Steel poles D Wooden poles, steel poles,  RCC and PCC poles and steel towers Answer : D Explanation :
66.
 Two condensers of capacity  2F  and  3F  are connected in series, a third condenser of  1F  is connected in parallel to them, the resultant capacity in  Farad (F)  will be  _________ A 6 F B 5/11 F C 5/6 F D 11/5 F Answer : D Explanation :
67.
 The conductivity of aluminium as compared to copper is A 1 B 0.7 C 0.6 D 0.5 Answer : C Explanation :
68.
 What is the type of insulator used for holding the  HT overhead conductor on straight running of poles A Post insulators B Pin-type insulators C Stay insulators D Shackle insulators Answer : A Explanation :
69.
 The type of lamps having highest illumination efficiency is A Mercury vapour lamp B Incandescent lamp C Sodium vapour lamp D Fluorescent lamp Answer : C Explanation :
70.
 At what level of current flow during electric shock death is possible A 1 to 8 milli amp B 50 to 100  milli am C 10 to 20  milli amp D 20 to 50  milli amp Answer : B Explanation :
71.
 Material used for making small rating fuses is A Aluminium B Copper C Silver D Lead and tin Answer : D Explanation :
72.
 In the circuit breaker, the arcing contacts are made of A Electrolytic copper B Copper tungsten alloy C Aluminium alloy D Porcelain Answer : B Explanation :
73.
 The main consideration in designing Distributor is A Transmission voltage B Resistance C Voltage drop D Current carrying capacity Answer : C Explanation :
74.
 When in dry condition human body resistance is around A 100 KΩ B 10 KΩ C 1 KΩ D Zero Answer : A Explanation :
75.
 The electric flux and field intensity inside a conducting sphere is  _________ A Zero B Maximum C Uniform D Minimum Answer : A Explanation :
76.
 Enclosure of motor is made from A Copper B Aluminium C Cast iron D Laminated sheath Answer : C Explanation :
77.
 The unit of plain angle is A Radian B Steradian C Lux D wb Answer : A Explanation :
78.
 The air delivery of fan is indicated by A Km3/min B mm3/min C m3/min D cm3/min Answer : D Explanation :
79.
 Which of the following will need the highest level of illumination A Proof reading B Bed rooms C Hospitals wards D Railway platforms Answer : A Explanation :
80.
 The source of illumination for a cinema projector is  __________ . A Incandescent lamp B Mercury vapour lamp C Sodium lamp D Carbon arc lamp Answer : D Explanation :
81.
 Which of the following motor is suitable for driving cranes, hoists, centrifugal pumps, conveyor belt etc A DC series motor B DC shunt motor C DC compound wound motor D Any of these Answer : A Explanation :
82.
 The main application of indirect arc furnace is to melt A Iron B Steel C Non-ferrous metals D None of these Answer : C Explanation :
83.
 The germanium crystal behaves as an insulator at A 00 K B 1730 K C 50 K D None of these Answer : A Explanation :
84.
 In p-n junction with no external voltage, the electric field between the acceptor and the donor ions is called a A Barrier B Threshold C Peak D Path Answer : A Explanation :
85.
 The common emitter transistor circuit has A High gain B Low gain C Negligible gain D No gain Answer : A Explanation :
86.
 The circuit that provides the best stabilisation of operating point is A Base resistor is B Collector feedback bias C Potential divider bias D None of these Answer : B Explanation :
87.
 In an amplifier the maximum power transfer to the load resistance should be A As small as possible B As large as possible C Equal to the value of the input resistance of the amplifier D Equal to the value of the output increases Answer : C Explanation :
88.
 In a synchronous motor the rotor copper losses, are met by A Armature input B D.C. source C Motor input D Supply lines Answer : B Explanation :
89.
 The change of  D.C. excitation of a synchronous motor changes A Motor speed B Applied voltage of the motor C Power of factor D All option are correct Answer : C Explanation :
90.
 The advantage of stationary armature of a synchronous machine is A Reducing number of slip rings on the rotor B Difficulty of providing high voltage insulation on rotor C Armature is associated with large power as compared to the field circuits D All option are correct Answer : D Explanation :
91.
 In which of the following motors the stator and rotor fields rotate simultaneously A Reluctance motor B Universal motor C D.C. motor D Synchronous motor Answer : D Explanation :
92.
 In a 3-phase synchronous motor, , if the direction of its field current is reversed A The wilding of the motor will burn B The motor will stop C The motor will run in the reverse direction D The motor continue to run in the same direction Answer : D Explanation :
93.
 The back e.m.f. of a synchronous motor depends on A Speed B Load C Load angle D All option are correct Answer : C Explanation :