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Electricity assignment 1, Friday, December 31, 2021, 11:35 AM, ONE MARK QUESTIONS, 1., List any two factors on which resistance of a conductor depends., 2. When is potential difference between two points said to be 1 volt?, 3. Mention one reason why tungsten is used for making filament of electric, lamp., 4. (a) Name the instrument/device used to measure electric current in a circuit., (b) How is an ammeter connected in a circuit to measure current flowing through, it?, 5. State a difference between the wire used in the element of an electric, heater and in a fuse wire., 6. Power of a lamp is 60 W. Find the energy in joules consumed by it in 1 s., 7. Why do we use copper and aluminium wire for transmission of electric, current?, 8. Define electric circuit. Distinguish between open and closed circuit., 9., Nichrome is used to make the element of electric heater. Why?, 10. Draw a schematic diagram of an electric circuit consisting of a battery of two, cells each of 1.5 V, 5 W, 10 W and 15 W resistors and a plug key, all, connected in series., 11. Out of the two, a toaster of 1 kW and an electric heater of 2 kW, which has a, greater resistance?, 12. State which has a higher resistance a 50 W or a 25 W lamp bulb and how, many times?, 13. Define resistivity of a material., 14. A cylinder of a material is 10 cm long and has a crosssection of 2 cm2. If its, resistance along the length be 20 ohm, what will be its resistivity in number, and units?, TWO MARK QUESTIONS, 15. Calculate the number of electrons that would flow per second through the, cross- section of a wire when 1 A current flows in it., 16. How much current will an electric bulb of resistance 1100 W draw from a, 220 V source? If a heater of resistance 100 W is connected to the same, source instead of the bulb, calculate the current drawn by the heater., 17. (a) What are the values of mA and m A?, (b)Draw the symbols of battery and rheostat., 18. Give reason for the following:, a. Tungsten used almost exclusively for filament of electric lamp., b.Why do we use copper and aluminium wires for transmission of electric current?, 19. What is the resistance of an ideal voltmeter?, 20. State the factors on which the heat produced in a current carrying conductor, depends. Give one practical application of this effect., 21. List in a tabular form two differences between a voltmeter and an ammeter., 22. A large number of free electrons are present in metals yet no current flows, in the absence of electric potential across it. Explain the statement with, reason., 23. Elements of electric toasters and electric iron are made of an alloy rather, than a pure metal, Give two reasons to justify the statement., 24. A thick wire and a thin wire of the same material are successively connected, to the same circuit to find their respective resistance. Which one will have, lower resistance? Give reason., 25. Why do the wires connecting an electric heater to the mains not glow while, its heating element does?