| 1. | In dc generator, wave winding is used for which type of machines ? | |
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high voltage low current
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high current low voltage
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high voltage high current
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low voltage low current
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Report Question| 2. | The space to height ratio in illumination lies between ? | |
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1 to 200
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1 to 20
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1 to 2
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1 to 2000
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| 3. | Moulded case circuit breaker is used for ? | |
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over load and short circuit protection
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over load protection
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short circuit protection
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open circuit protection
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| 4. | Which of the following will need lowest level of illumination ? | |
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Displays
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Fine engraving
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Railway platform
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Auditoriums
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| 5. | A mercury vapour lamp gives ? | |
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Pink light
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Yellow light
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Greenish blue light
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White light
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| 6. | Heat is transferred simultaneously by conduction, convection and radiation ............ ? | |
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Inside boiler furnaces
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During melting of ice
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Through the surface of the insulated pipe carrying steam
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From refrigerator coils to freezer of a refrigerator
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| 7. | Heavy-duty steel-works cranes having wide load variations are equipped with ? | |
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DC series motors
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Plain squirrel cage induction motors
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Wound-rotor induction motors
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Synchronous motors
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| 8. | In induction heating ? | |
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Heat is produced due to currents induced in the charge by electro-magnetic action.
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The resistance of the charge must be low and voltage applied must be high in order to produce sufficient heat
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Magnetic materials can be easily treated in comparison to non-magnetic materials
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all option are correct
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| 9. | The depth of penetration , in the case hardening of a steel pulley, required is 105mm. The relative permeability is unity and the specific resistance for steel is 5x10^-7 0hm-m. Determine the frequency required. ? | |
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56.3 KHz
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46.7 KHz
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52.7 Khz
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58.6 KHz
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| 10. | When an electron breaks a covalent bond, and moves away ? | |
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the semiconductor becomes conductor
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a valency is created in broken covalent bond
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the conductivity of the material increases
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More ions are produced
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