Basic of Electricity PDF

ELECTRICIAN (BASIC OF ELECTRICITY) S.K. Jha 40 3 (fo|qr dk ewy) CHAPTER (Atom) : Ampere-Second...

ELECTRICIAN (BASIC OF ELECTRICITY) S.K. Jha 40 3 (fo|qr dk ewy) CHAPTER (Atom) : Ampere-Second + 1.6 × 10–19 – 1.6 × 10–19 Q ne Q= (Free Electrons) : n= e= (Coulomb's law) q1 q2 r F q1 q2 — (i) F — (ii) (i) (ii) F (Charge) : F=K K= S.I. (Coulomb) C.G.S. F= 0 state coulomb 1 1 = emu 3 109 esu 0 = 8.85 × 10–12 10 emu–Electro magnetic unit K = 9 × 109 esu–Electro static unit Aash Exam  ELECTRICIAN (BASIC OF ELECTRICITY) S.K. Jha 41 emf (Charge Density) : emf (i) (Linear Charge density) ( ) (Potential Difference) : (ii) (Surface charge density) ( ) cm–2 (Electric Field) : (iii) (Volume Charge density) ( ) cm–3 (Electro Motive Force) [EMF] :– v (Electric Lines of Force) : (Potential) : J/C Aash Exam  ELECTRICIAN (BASIC OF ELECTRICITY) S.K. Jha 42 R (Intensity of Electric Field) : 'q' 'F' AC , DC ( , S.I N/C NC–1 V = IR (Electric Current) : (Resistance) : S.I. Ampere (C/s) R 6.28 × 1018 ( ) 1A 1.0049 3 × 108m/s (i) (Temperature) (ii) (Nature of substance) (Ohm's Law) : (iii) (Length) voltage — (i) (iv) (Cross Sectional Area) or, Aash Exam  ELECTRICIAN (BASIC OF ELECTRICITY) S.K. Jha 43 1 m 1 mho /m 1 = siemen m–1 m x x x x2 (Combination of Resistances) : 1 — R — (ii) A (i) (Series) (i) (ii) (ii) (Parallel) l (i) (Series Combination) : R A or, R l A (Rho) ( ): R= voltage RA MCB, l m2 SI = m m (ii) (Parallel Combination) SI m (Conductance) : G = Ohm–1 = Mho = Simen SI Ohm –1 ( –1 ) = ( ) = Mho = Simen or, (Specific Conductance) voltage (Sigma) Aash Exam  ELECTRICIAN (BASIC OF ELECTRICITY) S.K. Jha 44 (Wheatstone Bridge) : Note : AC — AC DC 4 (L N2) (Power) : V = IR I= Note : S.I. watt (W) 1 1 = 746 watts Inductor 1 = 735.5 watts kWh 1 kWh = 1.34 H.P (inductance) (Capacity) : SI (H) L Q V or, q = CV or, C L1 L2 L3 A B S.I. C/volt C volt–1 LAB = L1+L2+L3 F 1 F = 10–6 F 1F = 96500 coulomb L1 L1 L2 L2 A B A L3 B 711 F L.L 1 1 1 1 L AB 1 2 L1 L2 L AB L1 L2 L3 1 1 1 L AB L1 L2 D S W L1. L2. L3 L AB (L1L2 ) (L2L 3 ) (L 3L1 ) Aash Exam  ELECTRICIAN (BASIC OF ELECTRICITY) S.K. Jha 45 o A C M H A d (i) (A) (ii) (d) (Capacitor) : (iii) ( 0) (Di-electric Constant) : AC DC DC AC 1 K K K o A C d ~ Polarise/Non Polarise : (Polarised Dielectric Material) (Parallel Plate Capacitor) : HCl, H2O d H2, CO2, N2, O2 + – + – Polarized + – Non-Polarized + – + – Polarized (+), (–) Non Polarized Symbol Polarized DC Non-Polarized Voltage Vc AC Aash Exam  ELECTRICIAN (BASIC OF ELECTRICITY) S.K. Jha 46 Polarised non- AC/DC Polarised 1. 100V-3000V 500µF Non Polarised AC 2. 100V-100KV 300PF AC DC 3. 100-500V 10–3 Non- AC 10µF Polarised 4. 2V-3KV 10PF AC 0.1µF Non- PCB Polarised 5. 1V-1KV 1PF Polarised DC 100µF Noise (Al2O3) 1 PF = 10–12 F 1.5 F to 2.5 F (Combintion of Capacitors) : (i) (series) (ii) (Parallel) (i) voltage (ii) Aash Exam  ELECTRICIAN (BASIC OF ELECTRICITY) S.K. Jha 47 j I1 I= Ampere – m–2 (Types of Electric Current) : I2 (i) (Direct Current) DC :– I I3 (DC) (Electro-Plating) (Arc-welding) (Battery-charging) Capcitor (ii) (Alternating Current) AC :– Single phase motor (AC) parallel power factor AC Alternator (Domestic Applications) (Current Density) : (Industrial field) Aash Exam  ELECTRICIAN (BASIC OF ELECTRICITY) S.K. Jha 48 AC DC t = time (second) AC DC P = Power 1. AC 1. DC Battery charging Battery charging V = Voltage 2. AC 2. DC 1 (BTU) 36 × 105 (Electric Iron) 3. 3. (Heater) (Bulb) 4. 50 Hz 4. DC 0 Hz Note : +3% 5. AC 5. DC (0) 6. 6. Ammeter Voltmeter Ammeter Voltmeter AC DC (Electric Iron) : AC (0) 7. AC 7. Red hot wire Ammeter (Red hot wire) D.C Ammeter RMS 8. AC Battery 8. DC Battery 9. AC Transformer 9. DC Transformer 10. AC DC 10. DC AC Rectifier Inverter (Effects of Electric Current) : (i) (Heating Effect) (Heater) : (Joule) H= (J) I= (A) R= ( ) Aash Exam  ELECTRICIAN (BASIC OF ELECTRICITY) S.K. Jha 49 Brazing 450°C filler material Nichrome (Ni + Cr) filler material copper-zinc Cu-Ag, Al-Si Cu-Ag (Bulb) : Brazing (Borax) N2 Ar Brazing joint Brazing strength filler material Brazing Soldering : —3380°C Brazing : Soldering workpiece filler material solder Brazing Brazing Aash Exam  ELECTRICIAN (BASIC OF ELECTRICITY) S.K. Jha 50 Ions 0.0075 0.05mm (Copper) (Zinc) G.I Electrolytic cell Voltameter Raw Spirits of Salt Solder + 450°C Cathode Soldering joint Brazing joint Note : Soldering Brazing (M) (Q) Welding m Q (i) > Brazing > Soldering or, m I (ii) > Brazing > Soldering (ii) (Magnetic Effect) Z= Z SI Kg/C H.C. Orsted (Cell) (Galvanometer) (Electro plating) (Ammeter) (Metal extraction) (Volt meter) (Electric Bell) (Printing) (Fan) (Motor) DC (iii) (Chemical effect) anode (iv) (Gas Ionisation Effect) Aash Exam  ELECTRICIAN (BASIC OF ELECTRICITY) S.K. Jha 51 (ii) (K.V.L./loop law) (loop) X-rays voltage Node, Loop Mesh R1 I + – Loop I + Mesh + I R2 Vs – Loop Mesh, loop loop, Mesh – Vs + (– IR1) + (–IR2) = 0 Vs = IR1 + IR2 Vs = I(R1 + R2) Vs = IRT RT = R1 + R2 KVL — (+) (–) Voltage (–) loop : abcda, abca, adca (–) (+) Voltage (+) Mesh : abca, adca (Node) : junction Voltage (–) (Kirchhoff's Law) : Q. 12 V emf 1 (i) (K.C.L/Junction Law/Node Law) : 10 V emf 1 — (Node) (A) 1 A (B) 2 A (C) 4 A (D) 11 A Sol. KVL Law — –10. + (–I × 1) – (I × 1) + 12 = 0 2 – 2I = 0 – 2I = – 2 I = 1A (Electrical Load) : Ia + Ib + Ie + If = Ic + Id Load Load (Short circuit) : Ex : i3 Sol. 12A + 10A + i3 = 20A + 30A Short circuit (R) i3 = 50 – 22 Voltage i3 = 28 A Aash Exam  ELECTRICIAN (BASIC OF ELECTRICITY) S.K. Jha 52 (Open circuit) : V = IR v av v aI I aI I av R= V R ( I = 0) 0 RADAR Radio detection and ranging R= Voltage ( ) 1 = 6.25 × 1018 electron (Varistor) : (VDR) = + = Q. 220 V, 40 5 5 30 1 — Sol. = KVL = = 30 kWh KCL 30 Unit Kelvin D.C. VDR, LDR A.C. 17-21 KV/mm Aash Exam  ELECTRICIAN (BASIC OF ELECTRICITY) S.K. Jha 53 OBJECTIVE QUESTIONS PREVIOUS YEAR (a) (Neither series nor parallel) 1. (b) (Series parallel circuit) In a series combiantion of resistances : (c) (Series circuit) [RRB, ALP/Tech. 23 Jan, 2019 (Shift-2)] (d) (Parallel circuit) (a) (The voltage remains same) Sol. (c) (b) (The current and voltage remain same) (c) (The current and voltage both vary) Req = R1 + R2 + R3 +.............. + Rn (d) (The current remains same) Sol. (d) 4. Ohm's law can be applied to [RRB, ALP/Tech. 22 Jan, 2019 (Shift-2)] (a) (Resistor) (b) (Rectifier) 2. 2 3 6 (c) (Transformer) (d) (Zener Diode) Three resistances of 2 ohms, 3 ohms and 6 ohms Sol. (a) are connected in parallel. The total resistance of the combination is: [RRB, ALP/Tech. 23 Jan, 2019 (Shift-3)] (a) 11 (b) 1 V R V (c) 36 (d) 3 V= IR Sol. (b) 1 R= I V= R1 R2 R3 I= R = Req 1 1 1 1 R e q R1 R2 R3 5. amp- 1 1 1 1 What will be the value displayed an amp-meter that Re q 2 3 6 is shown in the below figure ? 1 3 2 1 + Re q 6 A + – Req = 1 50V 10 3. 10 ________ A circuit in which resistances are connected end to so that there is only one path for current to flow is [RRB, ALP/Tech. 23 Jan, 2019 (Shift-2)] called a _________. (a) 2.5A (b) 2A [RRB, ALP/Tech. 23 Jan, 2019 (Shift-3)] (c) 1A (d) 1.5A Aash Exam  ELECTRICIAN (BASIC OF ELECTRICITY) S.K. Jha 54 Sol. (a) 8. Which among the following, remains same in a I series circuit ? + [RRB, ALP/Tech. 23 Jan, 2019 (Shift-3)] A (a) (Power) (b) (Current) – 50V (c) (Voltage) (d) (Resistance) 10 Sol. (b) 10 V= I= R= 9. 'M' V = IR What is the formula to calculate the mass 'M' (R) = 10 + 10 = 20 deposited in the electrolysis process ? [RRB, ALP/Tech. 23 Jan, 2019 (Shift-1)] V 50 (I) = = 2.5 Amp (a) M = IT/Z (b) M = ZIT R 20 (c) M = ZT/I (d) M = ZI/T 6. 10 A 10 Sol. (b) 'M' M = ZIT A current of 10 A flows through a resistance of 10. cathode The power dissipated is: (M) (Q) [RRB, ALP/Tech. 23 Jan, 2019 (Shift-1)] (a) 100 W (b) 1000 W m Q Q (c) 10 W (d) 10000 W Sol. (b) m I I t m = ZIT (I) = 10A z= (R) = 10 z S.I. kg/C 10. 10 100 V DC =P P = I2R = (10)2 × 10 A 10 ohm resistor is connected across a 100 V DC = 100 × 10 source. The value of current flowing through the P = 1000 (W) circuit is: 7. [RRB, ALP/Tech. 23 Jan, 2019 (Shift-1)] In the case of direct current : (a) 10 A (b) 100 A [RRB, ALP/Tech. 23 Jan, 2019 (Shift-3)] (c) 1 A (d) 110 A (a) Sol. (a) (Magnitude and direction of current R = 10 changes with time) V = 100 volt (b) I=? (Magnitude of current changes with V = IR time) V 100 I 10A Ans. (c) (Magnitude and R 10 direction of current remains constant) 11. (d) (Magnitude of current _______ remains constant) When resistors are connected in series, the current Sol. (c) flowing through each resistor is [RRB, ALP/Tech. 23 Jan, 2019 (Shift-1)] DC Battery Charging (a) (Zero ) (b) (Different) (c) (Same as applied Voltage) DC 0 Hz (d) (Constant) Aash Exam  ELECTRICIAN (BASIC OF ELECTRICITY) S.K. Jha 55 Sol. (d) 15. A spelter used in brazing is commonly made of [RRB, ALP/Tech. 23 Jan, 2019 (Shift-1)] voltage (a) (Rosin iron base and lead alloy) 12. 230 V (b) (Copper base 10A and silver alloy) The input power of an electric heater that draws to (c) (Lead sulphide) A at 230V supply source is : (d) (Zinc Chloride ) [RRB, ALP/Tech. 23 Jan, 2019 (Shift-3)] Sol. (b) (a) 230 W (b) 2300 W (c) 23 W (d) 0 W Sol. (b) V = I= 450ºC R= V2 P= = VI = I2R = R 16. _____ V = 230V The temperature controlling of an electric iron is I = 10A done using : (P) = VI [RRB, ALP/Tech. 23 Jan, 2019 (Shift-2)] = 230 × 10 (a) (Bimetallic strip) P = 2300 watts (b) (Thermistor) 13. (c) (Resistance temperature Which one of the following is an insulator ? detector) [RRB, ALP/Tech. 23 Jan, 2019 (Shift-1)] (d) (Thermocouple) (a) (Copper ) (b) (Silver) Sol. (b) (c) (Plastic) (d) (Iron) Sol. (c) 14. _______ The heating element in a toaster is made of __ wire. (a) [RRB, ALP/Tech. 23 Jan, 2019 (Shift-1)] (a) /Kanthal (b) (b) /Nickel 17. 20 0.75 A (c) /Nichrome EMF (d) /Curponickel Sol. (c) Element Composition Safe operation Temp A battery is connected to a resistance of 20 If a Cr, Al, Co, Fe 1300ºC current of 0.75 A has to be produced, what should Ni— be the EMF of the battery ? [RRB, ALP/Tech. 23 Jan, 2019 (Shift-1)] Ni = 80% Cr = 20% 1150ºC (a) 20 V (b) 15 V Cu = 55% Ni = 45% 400ºC (c) 5 V (d) 30 V Sol. (b) R = 200 I = 0.75A V = IR = 0.75 × 20 = 15V Ans. Aash Exam  ELECTRICIAN (BASIC OF ELECTRICITY) S.K. Jha 56 18. (c) (Current controlled voltage source) When an electric current pass through a (d) (Current controlled current conducting solution, there is a change in color of source) the solution. What does it indicate ? Sol. (d) [RRB, ALP/Tech. 23 Jan, 2019 (Shift-1)] v av v aI I aI I av (a) (Heating effect of current) (b) (Chemical effect to current ) (c) (Magnetic effect of current) (d) (The lighting effect of current) I i Sol. (b) V v V i I v 21. Among the following, which material is a good conductor os electricity ? [RRB, ALP/Tech. 23 Jan, 2019 (Shift-3)] (a) (Silver) (b) (Glass) (c) (Porcelain) (d) (Rubber) 19. Sol. (a) Ohm's law states that: [RRB, ALP/Tech. 23 Jan, 2019 (Shift-1)] (a) R = I × V (b) V = R/I (c) I = V/R (d) I = V × R S.I. Mho Simen V 22. ______ Sol. (c) I R Conductance is defined as reciprocal of : voltage [RRB, ALP/Tech. 23 Jan, 2019 (Shift-3)] (a) (Resistance) V I V IR (b) (Capacitance) R (c) (Susceptance) V volt (d) (Inductance) R ohm I ampere Sol. (a) 20. I I G + 1 G= R Iout= i R= (S) or mho – ( ) Identify the circuit in the given figure: I I + Iout= i 23. Which among the following, remains same in a – series circuit ? [RRB, ALP/Tech. 23 Jan, 2019 (Shift-1)] [RRB, ALP/Tech. 23 Jan, 2019 (Shift-3)] (a) (Voltage controlled current (a) (Power) (b) (Current) source) (c) (Voltage) (d) (Resistance) (b) (Voltage controlled voltage Sol. (b) source) Aash Exam  ELECTRICIAN (BASIC OF ELECTRICITY) S.K. Jha 57 R1=4K R2= K V=5V 24. SI V R1 V1 What is the SI unit of electromotive force ? R1 R 2 [RRB, ALP/Tech. 22 Jan, 2019 (Shift-1)] V R2 (a) Volt (b) Newton V2 (c) Ampere (d) Webers R1 R 2 Sol. (a) S.I. V R2 V = V2 = R1 R 2 5 1 5 V (1 4) 5 25. 100V, 50 Hz = 1 Volt 10 27. A coil is connected across a 100V, 50 Hz supply. If Which of the following is used as the heating unit the impedance of the circuit is 10 ohsm, the currnt of an electric kettle ? flowing through the circuit is........ [RRB, ALP/Tech. 22 Jan, 2019 (Shift-3)] [RRB, ALP/Tech. 22 Jan, 2019 (Shift-1)] (a) Inductive filament (a) 1000 A (b) 10 A (b) Concealed wire in metal tube (c) 1 A (d) 100 A (c) Flat wire sealed Sol. (b) (d) Open filament (V) = 100 V Sol. (b) (Z) = 10 (i) = 100 I= 10 amp 10 26. What is the value displayed by the voltmeter in the given picture ? + 4K 5V 28. E e.m.f. + 1K V – The electromotive force E or e.m.f. is the energy [RRB, ALP/Tech. 22 Jan, 2019 (Shift-1)] provided by a cell per coulomb of charge passing (a) 1 A (b) 4 V through it is measured in.......... (c) 4 A (d) 1 V [RRB, ALP/Tech. 22 Jan, 2019 (Shift-3)] Sol. (d) (a) Joules (b) Volts (c) Tesla (d) Amperes R1 R2 Sol. (b) E emf + V1 – + V2 – V + – Aash Exam  ELECTRICIAN (BASIC OF ELECTRICITY) S.K. Jha 58 emf E r 31. SI R The SI unit of electrical power is : (R + r) [RRB, ALP/Tech. 23 Jan, 2019 (Shift-2)] (a) (Coulomb) (b) (Kilowatt) V (c) HP (d) (Joule) Sol. (b) SI r + – (I) (A) E (V) (V) (P) (W), (KW) A (E) (J), (kwh) R S (R) (C) Note : E 1 kW = 100W I= R r 1 kWh = 1 unit = 3.6 × 106 Jule 1 H.P = 746 W E V 32. r R V ______ 29. Temperature control in bridge measurement is The principle behind the process of electrolysis is ? required because a difference in temperature will [RRB, ALP/Tech. 22 Jan, 2019 (Shift-3)] cause a difference in : [RRB, ALP/Tech. 23 Jan, 2019 (Shift-2)] (a) Coulomb's law (a) (Frequency) (b) (Inductance) (b) Lenz's law (c) (Capacitance) (d) (Resistance) (c) Faraday's law Sol. (d) (d) Ohm's law Sol. (c) R = T = 30. _______ 33. 2V 110 V In an electric iron, the transfer of heat from coil to AC base plate is mainly through : [RRB, ALP/Tech. 23 Jan, 2019 (Shift-2)] In a series lamp circuit, each bulb is rated for 2V. (a) (Capacitance) (b) (Radiation) Calculate the number of bulbs to be connected in (c) (Conduction) (d) (Convection) series to run on a 110 V AC line. Sol. (c) [RRB, ALP/Tech. 23 Jan, 2019 (Shift-2)] (a) 60 (b) 55 (c) 65 (d) 70 Sol. (b) 2V 110 Aash Exam  ELECTRICIAN (BASIC OF ELECTRICITY) S.K. Jha 59 Supply Voltage V2 V2 = M P= Volt RT 3R 110 V2 = = 55 3M...(i) 2 R 34. R [RRB, ALP/Tech. 23 Jan, 2019 (Shift-3)] (a) (Thickness) R (b) (Distance between the plates) (c) (Nature of the dielectric) R (d) (Area of the plates) Sol. (a) + – + – + – + – V + – V2 V 2 + – P= RT R 3 3V 2 Symbol P' = R V Voltage Vc P' = 3 × 3 M R 3M P' = 9 M 36. R1,R2 R3 10V, 20 V 30 V d If the voltage drop across individual resistor R1, R2 and R3 connected to a battery are 10V, 20V and 0 A r 0 A 30 V respectively. Then the total battery voltage C d d is: [RRB, ALP/Tech. 23 Jan, 2019 (Shift-3)] (a) 20V (b) 30V r = Relative Permittivity of material (c) 60V (d) Zero o = Permittivity of free space Sol. (c) d = Distance of Separation of Plates VR1= 10 V A = Area of Plate VR2= 20 V C = Capictance of Capacitor VR3= 30 V 35. 'M' +V – +V – +V – R1 R2 R3 Three Identical bulbs are connected in series and these together dissipate power 'M'. If now the bulbs are connected in parallel, then the power dissipated V will be : [RRB, ALP/Tech. 23 Jan, 2019 (Shift-3)] (a) M/3 (b) 3M KVL (c) 9M (d) M/9 Vtotal = V1+ V2 + V3 R R R Vtotal = 10 + 20 + 30 Vtotal = 60V 37. Sol. (c) Among the following, which metal is NOT usually + – preferred as flux for soldering applications ? V [RRB, ALP/Tech. 22 Jan, 2019 (Shift-1)] Aash Exam  ELECTRICIAN (BASIC OF ELECTRICITY) S.K. Jha 60 (a) Borax (b) Zinc Ammonium (a) (b) (c) (c) Ammonium chloride (d) Lead Sol. (d) 3T 40. The main purpose of flux in soldering is to ? [RRB, ALP/Tech. 22 Jan, 2019 (Shift-1)] (a) Keep the metal surface clean and oxide free (b) reduce melting point (c) ensure proper texture (d) reduce temperature Sol. (a) (i) (ii) 38. Soldering iron bit is made up of: 41. [RRB, ALP/Tech. 22 Jan, 2019 (Shift-2)] Which of the following is a unit of force? (a) (Tin) (b) (Steel) [RRB, ALP/Tech. 23 Jan, 2019 (Shift-1)] (c) (Brass) (d) (Copper) (a) Newton (b) Joule Sol. (d) (c) Volt (d) Ohms Sol. (a) SI = × F ma 39. The recommended configuration for soldering is ? [RRB, ALP/Tech. 22 Jan, 2019 (Shift-1)] CGS = 9m cm/s2 = (a) Lap joint (b) Wave joint 1 = (c) Scarf joint (d) Butt joint 1 cm/s2 Sol. (a) 42. The recommended configuration for soldering is : [RRB, ALP/Tech. 23 Jan, 2019 (Shift-2)] (a) (Wave joint) (b) (Butt joint) (c) (Lap Joint) (d) (Scarf joint) Aash Exam  ELECTRICIAN (BASIC OF ELECTRICITY) S.K. Jha 61 Sol. (c) 47. — [ISRO Tech., 2020] (a) (b) (c) ( 0) (d) Sol. (d) 43. The soldering proces is carried out in the temperature range. [RRB, ALP/Tech. 23 Jan, 2019 (Shift-1)] (a) 15 – 60ºC (b) 70 – 150ºC q1q2 (c) 180 – 250ºC (d) 300 – 500ºC F = Ke (e) undefined - false r2 Sol. (c) 180ºC 250ºC Ke = Ke = 9 × 109 N m2C–2 48. — [ALP, 2014] (a) (b) (c) LEVEL - I (d) 44. — [BSPHCL, 2019] Sol. (a) (a) (b) (c) (d) Sol. (c) +q – 1.6 × 10–19 (a) Isolated Charge 45. (a) (b) (c) (d) +q –q Sol. (c) (b) Unlike Charges 49. [Ordnance Factory, 2014] (a) (b) 46. — (c) (d) (a) (b) Sol. (b) (c) (d) Sol. (b) Aash Exam  ELECTRICIAN (BASIC OF ELECTRICITY) S.K. Jha 62 50. [JMRC, 2016 (a) (b) (c) (d) Sol. (b) 56. (a) (b) (c) (d) Sol. (d) 51. — [ALP, 2014] (a) (b) (c) (d) Sol. (c) ( ) 52. — [UPPCL, 2014] 57. — [JMRC, 2008] (a) AC (a) = (b) DC (b) = × (c) AC DC (c) = × (d) AC DC (d) = Sol. (c) AC DC Sol. (a) = (i) (ii) (iii) 58. — [UPPCL, 2018] 53. [HAL, 2015] (a) (a) 1 (b) 1 (b) (c) 1 (d) (c) Sol. (b) 1 (d) Sol. (b) 59. [ISRO Tech., 2016] 54. 1 [ALP, 2018] (a) (b) (a) 3.6 × 105 J (b) 36 × 105 J (c) 0.36 × 105 J (d) 36 × 104 J (c) (d) Sol. (b) 1 36 × 105 J Sol. (c) 1 1KWH BTU 1KWH = 1000 Watt-Hour 1KWH = 1000 × 3600 Watt-Sec 1KWH = 36 × 105 J 55. — [ALP, 2018] 60. (a) (b) (a) (b) (c) (d) (c) (d) Sol. (a) Sol. (c) Aash Exam  ELECTRICIAN (BASIC OF ELECTRICITY) S.K. Jha 63 S.I Sol. (d) = 61. 1000 (a) (b) (c) (d) 5 200 4 = Sol. (c) 1000 =4 1 0.50 4 0.5 × 4 = 2 Ans. 66. 3 , 2 5 12V 62. [UPPCL, 2021] (a) (b) (a) 8 (b) 10 (c) (d) (c) 4 (d) 2 Sol. (a) 3 2 5 Sol. (b) 10–6A 63. 1.5 150 V [JMRC, 2016] (a) 100 W (b) 500 W 12V (c) 15000 W (d) 1000 W R = R1 + R2 + R3 Sol. (c) = 3 + 2 +5 R = 1.5 , V = 150V = 10 Ans. 67. 6 6V V2 P= (a) 18 (b) 12 R (c) 6 (d) 2 150 150 = 1.5 6 = 15000 W Ans. Sol. (d) 64. 1500 W 4 6 [ISRO Tech., 2012] (a) 1 (b) 6 (c) 2.5 (d) 4 6 Sol. (b) P = 1500 Watt t = 4 hrs 12V = 1000 1 1 1 1 1500 4 = R R R = R 1 2 3 1000 1 1 1 60 = + + = =6 Ans. 6 6 6 10 65. 200–200 W 50 kWh 4 3 = — [ALP, 2018] 6 (a) 3.50 (b) 3.00 6 (c) 2.50 (d) 2.00 R= = 2 Ans. 3 Aash Exam  ELECTRICIAN (BASIC OF ELECTRICITY) S.K. Jha 64 68. 12V 14 6 Sol. (d) (a) 10 (b) 4.2 (c) 8.6 (d) 24 Sol. (b) 14 6 Ceq = C1 + C2 + C3 + C4 12V = 18 + 16 + 42 + 74 1 1 1 = 150 µF Ans. = R + R 72. 36 F 14 F R 1 2 [UPPCL, 2019] 1 1 = + (a) 50 F (b) F 14 6 3 7 10 = = (c) 3/32 F (d) F 42 42 Sol. (a) 36µF 42 R= = 4.2 Ans. 10 69. [JMRC, 2010] A B (a) (b) (c) (d) 14µF Sol. (d) Ceq = C1 + C2 = 36 + 14 = 50µF Ans. 73. 28 F 70. [ISRO Tech., 2016] c [UPPCL, 2018] (a) 64 F (b) 28 F (a) 4c (b) c/4 (c) 14 F (d) 56 F (c) 3/4 c (d) c Sol. (c) 28µF 28µF Sol. (a) C C A B C 1 1 1 C Ceq = C1 + C2 1 1 2 = + = A B 28 28 28 Ceq = C1 + C2 + C3 + C4 28 Ceq = = 14 µF Ans. =C+C+C+C 2 = 4C Ans. 74. 16 F, 16 F 32 F 71. 18 F, 16 F, 42 F 74 F (a) F (b) F (a) 15/64 F (b) 64/15 F (c) 64 F (d) 150 F (c) 56 F (d) 32 F Aash Exam  ELECTRICIAN (BASIC OF ELECTRICITY) S.K. Jha 65 Sol. (a) 1 1 1 1 1 16µF 16µF 32µF Ceq = C1 + C2 + C3 + C4 A B 1 1 1 1 1 1 Ceq = 16 + 16 + 16 + 16 1 1 1 Ceq = C1 + C2 + C3 1 1 1 1 1 1 1 1 Ceq = 16 = + + 16 16 32 16 Ceq = = 4µF Ans. 2 + 2 +1 4 = 79. [UPPCL, 2014] 32 32 (a) (b) Ceq = = 6.4 µF Ans. (c) (d) 5 Sol. (d) 75. — Volt- (a) [ALP, 2014] age (b) (c) V I (d) Sol. (b) V IR R V Volt R= = = Ohm ( I Ampere 80. 10–10 — [Ordnance Factory, 2017] 76. [ISRO Tech., 2020] (a) (a) (b) (b) (c) (d) (c) Sol. (b) (d) Sol. (b) 10–15m 10–10m 77. 100W, 200V — [HAL, 2015] (a) 100 (b) 200 (c) 400 (d) Sol. (c) P = 100W, V = 200V 81. — [HAL, 2015] V2 (a) (b) P= R (c) (d) V2 200 200 Sol. (a) R= = P 100 = 400 Ans. S.I (Coulomb) 78. 16 F C.G.S State Coulomb — [ALP, 2018] 82. 1 (a) 64 F (b) 8 F (combinations) (c) 32 F (d) — [JMRC, 2010] Sol. (d) 16µF 16µF (a) 9 (b) 3 A B 16µF 16µF (c) 1 (d) Aash Exam  ELECTRICIAN (BASIC OF ELECTRICITY) S.K. Jha 66 Sol. (c) 1 1 1 1 1 1 A B 86. — 1 1 1 [ALP, 2018] 1 1 1 1 Req = R1 + R2 + R3 1 1 1 1 1 1 1 Req = 1 + 1 + 1 = (a) 10 A (b) 5 A 1 (c) 20 A (d) 100 A 1 Req = Sol. (b) 10 3 1 1 1 3 RAB = + + = = 1 Ans. 3 3 3 3 83. Ampere second [UPPCL, 2021] I (a) (b) (c) (d) Sol. (a) Ampere – Second 100V Q Req = R1 + R2 + R3 Q = I.T = 10 + 5 + 5 = 20 V 100 I= = = 5A Ans. R 20 S.I 87. I — [UPRVNL, 2015] 84. — (a) 12 F (b) (a) (b) 6 A (c) 4 F (d) (c) 8A (d) 12 A Sol. (d) = Sol. (b) 4µF 4µF 4µF 9A + 6A = 3A + I A B 15 – 3 = I I = 12 A Ans. 1 1 1 1 88. C AB = C1 + C2 + C3 [Ordnance Factory, 2017] 1 1 1 1 (a) 4 mA (b) 9 mA C AB = 4 + 4 + 4 (c) 15 mA (d) 25 mA Sol. (b) 9 mA 1 1 1 = 4 S.I Ampere (Coulomb/Sec) 4 CAB = µF Ans. 3 85. —[HAL, 2015] (a) (b) (c) (d) 89. 20 Sol. (a) [ALP, 2018] (a) 60 (b) 2 (c) (d) Aash Exam  ELECTRICIAN (BASIC OF ELECTRICITY) S.K. Jha 67 91. [UPPCL, 2015] Sol. (d) (a) P = I2R (b) P = V.I 20 20 (c) P= (d) P = Sol. (d) P = VI.................(i) 20 40 V = IR (i) V P = (IR) × I P I 2R A B V 20 (i) I= R 1 1 1 V Req = R1 + R2 P=V× R 1 1 = + V2 20 40 P R 2 1 = 92. [JMRC, 2008] 40 (a) mA < A (b) A < A 40 (c) A < mA (d) < mA Req = Ans. 3 Sol. (d) 1µA = 10–6 A 90. 10 1mA = 10–3A 1 nA = 10–9A 1 pA = 10–15A (a) 10 (b) pA < nA < µm < mA < A 93. 2 [UPPCL, 2018] (c) (d) 40 (a) 2000 (b) 200 (c) 20 (d) 1000 10 Sol. (a) Sol. (b) 94. [ISRO Tech., 2016] 10 10 (a) (b) (c) 1 2 (d) Sol. (b) A 10 B 30 A 10 B 1 1 1 R eq = R 1 + R 2 95. 5 60J 1 1 1 R eq = 30 + 10 5 1 (a) 15 J (b) 30 J 1 3 (c) 60 J (d) 120 J R eq = 30 Sol. (b) H = I2RT 30 Req = = 7.5 Ans. 4 Aash Exam  ELECTRICIAN (BASIC OF ELECTRICITY) S.K. Jha 68 H R k k C/ Volt 60 J 30 J 102 [ALP, 2018] (a) (b) 96. 3 30 (c) (d) — [UPPCL, 2021] Sol. (b) (a) 3.3 (b) 10 (c) 90 (d) 30 Sol. (b) Q = It 103. IS Q I = (a) (b) t (c) (d) 30 Sol. (d) IS = = 10 A Ans. 3 97. [Ordnance Factory, 2014] (a) (b) Phase (c) a&b (d) Not Live Sol. (b) 104. BIS — [UPPCL, 2019] (a) S.I ampere per square meter (b) (c) "J" (d) 98. [UPPCL, 2014] Sol. (b) BIS (a) (b) (c) (d) Sol. (b) ' ' 1947 l R = 105. (class of fire) A [Ordnance Factory, 2015] = (a) A (b) T 99. 10 (c) B (d) D (a) 10 M (b) 0.1 Sol. (d) D (c) 100 M (d) 1 M D Sol. (a) 'D' 100. (capacitance) [ALP, 2018] (a) (b) (c) (d) S.I Sol. (b) 106. I.E. ______ [UPPCL, 2021] (a) (b) (c) (a) (b) (d) Sol. (c) I.E 101. (dielectrics) [JMRC, 2008] (a) (b) (c) (d) Sol. (c) (dielectrics) 1 Aash Exam  ELECTRICIAN (BASIC OF ELECTRICITY) S.K. Jha 69 107. Sol. (a) KCL [ISRO Tech., 2012] (a) (b) KCL (c) (a) (b) (d) (Node) Sol. (a) A.C 113. 12V 3.6 mA [JMRC, 2016] J/C (a) 3.3 (b) 33 108. (dielectrics) [UPPCL, 2016] (c) 22 (d) 2.2 (a) Sol. (a) V = 12 Volt, I = 3.6 mA (b) V = IR (c) (d) V 12 10 10 R= = = = 3.33 Sol. (c) I 6 3 1 114. [HAL, 2015] (a) VA (b) KWH AC DC (c) KV (d) KVA 109. Sol. (b) KWH [BSPHCL, 2019] (a) (b) (c) (d) Sol. (d) (KWH) = 1000 = J/C 1000 110. 115. 4 pF (a) 1000 (capacitance) [UPPCL, 2014] (b) 10 (a) 8 pF (b) 16 pF (c) 100000 (c) 2 pF (d) 4 pF (d) 100 [ISRO Tech., 2020] Sol. (c) C1 C2 Sol. (c) 100000 S.I ( ) 1 1 1 m Ceq = C1 + C2 Simen Mho 111. 20 0.75 1 1 1 1 1 2 Ceq = 4 + 4 = 4 = 4 (EMF) [ALP, 2014] 1 2 (a) 20 (b) 15 Ceq = 4 (c) 30 (d) 5 Sol. (b) R = 20 I = 0.75 A Ceq = 2pF V = IR 116. = 0.75 × 20 (a) (b) = 15 V (c) (d) 112. [Ordnance Factory, 2014]