Module 3 New Module 3 New quiz contains 52 question based on the syllabus for module 3 examination for B1.1, B1.3 and B2 category. The time limit for the quiz is 65 min. The number of attempts allowed are unlimited. All the best. Name 1. A potentiometer is a: Terminal device used to vary current 2 terminal device used to vary voltage 3 terminal device used to vary voltage None 2. In the Diagram the two unknown resistors are of equal value and their value is: 24 ohm 6 ohm 12 ohm None 3. If the time constant for a capacitor is 10us the time taken for the to reach the fully charged condition is approximately: 10 X 6.32 us 50us 10us None 4. A 40ohm resistor is connected to a 200 volt supply. The resultant power dissipated is: 8000 watts 1000 watts 800 watts None 5. A 12V battery has an internal resistance of 0.2 ohm. With a 5A load current flowing what is the potential difference of the battery? 12V 1V 11V None 6. An 8microF capacitor is connected in series with a 0.5 megaohm resistor. The DC voltage supply is 200V. Calculate the time constant. 1s 3s 4s 2s None 7. When comparing 2 alternating current waveforms, one is at its maximum value while the other is at zero. The two waveforms are: 45° out of Phase of opposite phase angle 90° out of Phase None 8. What will happen to the frequency if the number of revolutions increases? Becomes zero Increases Remains the same Decreases None 9. A 4 ohm resistor and an inductor of 3 ohms reactance are connected in series the impedance of the circuit is: 7 ohm 10 ohm 5 ohm None 10. The voltage waveform in an ideal inductance would be: In phase with the current 90° leading the current 90° lagging the current None 11. Resistance is: Proportional to the cross sectional area Inversely proportional to the cross sectional area Inversely proportional to the product of length and resistivity None 12. A coil induces 200 mV when the current changes at the rate of 1 amp per second. The inductance L is: 200 mH 100 mH 400 mH None 13. Two resistors in parallel. If they are of unequal value it is true that: The lowest ohmic value takes the largest current The highest ohmic value takes the largest current The both ohmic values takes the same current None 14. When the supply frequency increases, what happens to the capacitive reactance in the circuit? Decreases Increases Becomes zero Remains the same None 15. In the diagram the resultant current is: 2mA 1.5mA 10mA None 16. If the resistance of a conductor is 10Ω then it’s conductance is? 0.01 Siemens 0.1 Siemens 0.25 Siemens None 17. When capacitors are connected in series ___________ remains the same. Voltage across each capacitor Capacitance Charge None 18. An alternating current series circuit contains resistance of 100 ohms, XL reactance of 100 ohms and XC reactance of 100 ohms. The impedance will be: 100 ohms 33.33 ohms 300 ohms None 19. An inductor of 50mH is connected in series with a resistance of 10kΩ. The time taken for the current to reach 63.2% of the maximum is: 500 μS 5 μS 50 μS None 20. In an RLC circuit, the power factor is always Depends on the circuit Positive Zero Negative None 21. The generator characteristic of: high current and low voltage are found in a wave winding format low current and high voltage are found in a lap winding format high current and low voltage are found in a lap winding format None 22. Siemens is the unit name for: inductance and is given the symbol H conductivity and is given the symbol G resistivity and is given the symbol B None 23. A charge of 12 coulombs moves past a given point in 2 seconds. Intensity of the charge flow in amps is: 10 6 24 None 24. In order to produce a substantial voltage and current from photovoltaic cells they should be connected in: parallel with each other series parallel arrangement series with each other None 25. When a changing pressure is applied to opposite faces of a crystal: It distorts giving a mechanical energy output An electrical potential is generated It will be damaged because force should only be applied to adjacent faces None 26. What is the resistance and tolerance value of a resistor colour coded, yellow, Violet and brown: 47ohm +/-20% 4.7 ohm +/-10% 470 ohm +/-20% None 27. Connecting two 28volt 60 Amp/Hour batteries in parallel will produce: 28V 120A/H 28V 60A/H 56V 60A/H None 28. The total resistance of three resistors in series of values R1=60ohm R2=20ohm R3=10ohm is: 90ohm 6ohm 48ohm None 29. Lamination used in a transformer core: reduce efficiency reduce eddy current losses reduce copper losses None 30. N capacitors having capacitance C are connected in series, calculate the equivalent capacitance. C/N C CN N/C None 31. 5 amps passes through a 4 ohm resistor, the amount of power the resistor has to dissipate is: 100 watts 6.25 watts 20 watts None 32. What is the power factor of a series RLC circuit under resonance condition? 0 1 Infinity None 33. Calculate the charge in the 2F capacitor 200C 50C 100C None 34. Calculate the total capacitance 13F 10F 15F None 35. The point of coercivity occurs when the: magnetic flux is zero even though a magnetising force is being applied magnetic force applied causes the material to become magnetically saturated magnetic force reaches its peak positive of negative value None 36. An alternating electromotive force is applied to a pure resistance. Current and voltage : are in anti-phase are in phase phase angle dependent on frequency None 37. What is the total capacitance when three capacitors, C1, C2 and C3 are connected in parallel? 1/C1+1/C2+1/C3 C1/(C2+C3) C1+C2+C3 C2/(C1+C3) None 38. The unit of Siemens with the symbol G is: Resistance Conductance Reactance None 39. Resonance frequency occurs when XL=XC XL>XC XL<XC None 40. When making up electrolyte for lead acid batteries: it is safest to add water to acid it is safest to add acid to water equal quantities of water and acid should be used None 41. In a parallel circuit, with a number of resistors, the voltage across each resistor is Is divided equally among all resistors The same for all resistors Is divided proportionally across all resistors None 42. The voltage rating on a capacitor is the: voltage at which the dielectric breaks down if exceeded voltage that the capacitor becomes saturated and will accept no more charge maximum reverse voltage before the plates buckle None 43. Some materials emit electrons to a light source. These are: Photovoltaic cells Thermoelectric cells Piezoelectric cells None 44. Three capacitors of value 4uF, 6uF and 12uF are connected in parallel. The total circuit capacitance is: 20uF 2uF 22uF None 45. A Semi-conductor will have: eight electrons in the outer shell two electrons in the outer shell four electrons in the outer shell None 46. One of the laws of magnetism states-'the force between two magnetic poles of constant strength is: inversely proportional to the square of the distance proportional to the distance between them' inversely proportional to the distance between them' None 47. When the voltage across a capacitor increases, what happens to the charge stored in it? Becomes zero Decreases Increases None 48. In the diagram an unknown resistance is being measured using a Wheatstone bridge. The bridge is balanced. The unknown resistance is: 60 Ω 150 Ω 10 Ω None 49. In a wire wound resistor the length of wire is increased by four times and its cross sectional area is doubled. The resistance value is effectively: decreased by half doubled increased eight times None 50. The electrolyte solution used in an alkaline battery is: Lead Sulphate Potassium Hydroxide Sulphuric Acid None 51. Of the following phases, which two are 180 degrees apart? IR and IL VC and VL VL and VR None 52. Which among the following expressions relate charge, voltage and capacitance of a capacitor? Q=V/C Q=CV Q=C/V None 1 out of 1