Mains Electricity 1. Why is the cooker circuit wire very thick compared to the other circuit wires? Because the cooker draws a very large current which will be need to be carried safely through cooker circuit wireIt carries very small current Because it has neutral wire for earthing None of the mentioned Question 1 of 22 2. Why are aluminum cables preferred for transmitting electrical power over a long distance? It is a good conductor It is light in weight It is relatively cheap and available All of the above Question 2 of 22 3. Which of the following statements is CORRECT about a fuse? It used to safeguard against excess current in a circuit It is made up of a short thin wire (an alloy of copper and tin) Overcurrent makes the fuse wire get very hot and it melts All of the above Question 3 of 22 4. From the transformer, power is brought to the house through a two wire cable; Mention them Live and NeutralNeutral Dead and LiveEarth and LiveQuestion 4 of 22 5. Give the main importance of the national grid system To generate money quickly For safety reasons Ensures that power is available to consumers even when one of the power stations is shut down.None Question 5 of 22 6. Mention the overall level of voltage stepped down from the national grid to a local transformer? 5500V-110V 11000v-240V 11000v-440v None Question 6 of 22 7. Give the name of the bus bar to which all the neutral wires of a home consumer circuit are connected to: earth terminal live bus bar neutral bus bar main switch Question 7 of 22 8. How do you reduce power losses during transmission of electricity? By transmitting the power at high voltage and low currentBy transmitting the power at low voltage and high currentBy using strong insulated power cablesAll of the above Question 8 of 22 9. Which of the following is not among the items which are contained in a home consumer fuse box? Main switch Live bus bar Modern bus barNeutral bus barQuestion 9 of 22 10. Which kind of electrical appliance possess a risk of electric shock? The one which is earthedThe overloaded circuit The one which is not earthed None of the mentioned Question 10 of 22 11. Mention the dangers of high voltage transmission? The risk of electrical shock The risk of fire on nearby stations The harmful effects of strong electric field All of the above Question 11 of 22 12. What is the electrical power for domestic consumption? 11000 v 110v 240v 5500v Question 12 of 22 13. State the difference between a fuse and a circuit breaker's? Circuit breakers are made up of alloy of copper and tin unlike fusesA fuse is used in a fuse box while circuit breaker in a circuit Circuit breakers can be reset for use again once the fault has occurred but the fuse wire has to be replaced once it melts. All of the above Question 13 of 22 14. Why is the lighting wire very thin compared to the other circuit's? It carries very large current through Because it lacks no earthingIt carries smaller currents through None of the mentioned Question 14 of 22 15. Which of the following is NOT a source of Mains electricity supply? Geothermal energy The Force Wind Nuclear energy Question 15 of 22 16. Electrical Energy = POWER x TIME and its S.I UNIT IS J/s. True or False? False True Maybe None Question 16 of 22 17. Is it possible to step up or step down steady d.c voltage? Yes No Maybe None Question 17 of 22 18. A national grid is a system of power cables connecting all stations in a country to each other and finally to the consumers. True or False? False True Maybe None Question 18 of 22 19. Which type of circuit is often not earthed as a necessity? Cooker circuit Lighting circuit Main circuit None of the mentioned Question 19 of 22 20. Mention the name of the bus bar connected to the live wire Earth terminal Live bus bar Neutral bus bar Main switch Question 20 of 22 21. Name the electrical component used, to safe guard against excessive currents in a circuit Fuse boxFuseMeter None Question 21 of 22 22. Mention the bus bars contained in a consumer fuse box Earth terminal Live bus bar Neutral bus bar dead bus barQuestion 22 of 22 Loading...
