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    02 Electricity

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    dysonjonas269
    The document contains questions from past exams on the topic of electricity. It covers concepts of electrostatics, electrical resistance, power and cost of electricity. Example questions include calculating total resistance in circuits, power dissipated by appliances, and cost of running devices. Diagrams of electric circuits are provided with some questions.

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    © All Rights Reserved
    Download as PDF, TXT or read online from Scribd

    02 Electricity

    Uploaded by

    dysonjonas269
    19 views5 pages
    The document contains questions from past exams on the topic of electricity. It covers concepts of electrostatics, electrical resistance, power and cost of electricity. Example questions include calculating total resistance in circuits, power dissipated by appliances, and cost of running devices. Diagrams of electric circuits are provided with some questions.

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    02_Electricity

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    The document contains questions from past exams on the topic of electricity. It covers concepts of electrostatics, electrical resistance, power and cost of electricity. Example questions include calculating total resistance in circuits, power dissipated by appliances, and cost of running devices. Diagrams of electric circuits are provided with some questions.

    Copyright:

    © All Rights Reserved
    Download as PDF, TXT or read online from Scribd
    Download as pdf or txt
    19 views5 pages

    02 Electricity

    Uploaded by

    dysonjonas269
    The document contains questions from past exams on the topic of electricity. It covers concepts of electrostatics, electrical resistance, power and cost of electricity. Example questions include calculating total resistance in circuits, power dissipated by appliances, and cost of running devices. Diagrams of electric circuits are provided with some questions.

    Copyright:

    © All Rights Reserved
    Download as PDF, TXT or read online from Scribd
    Download as pdf or txt
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    2 Electricity

    1. Electrostatics

    2010-6.
    a. Mention any two appliances that use the principle of electrostatics. (2 marks)

    2008-4.
    e. Figure 4 is a diagram showing a charged rod brought close to metal can standing on an insulator.

    (i) Complete the diagram by indicating the induced charges on the can. (2 marks)
    (ii) Why was the can on an insulator?

    2. Electrical resistance

    2011-2.
    b. Explain the difference in total resistance between similar resistors connected in series and parallel.
    (4 marks)

    2009-4.
    a. What do the following electrical symbols stand for? (1mark)

    b. In a circuit, a 6 resistor and a 3 resistor are connected in parallel and an 8 resistor is


    connected in series with them.
    (i) Draw a circuit diagram using the given information. (2marks)
    (ii) Calculate the total resistance in the circuit. (5marks)
    2 Electricity - Questions
    c. Figure 5 is a diagram of an electric circuit for a house.

    (i) What type of circuit is shown in the diagram? (1mark)


    (ii) Give two reasons why this type of circuit is preferred for wiring houses. (2marks)
    (iii) Explain the importance of including the device labeled X in the circuit in Figure 5. (3marks)
    (Iv) Give any one appliance where device X is used. (1mark)

    2007-4.
    c. Figure 2 is a diagram of an electric circuit.

    (i) If S1 is closed and S2 is open, calculate the reading of the ammeter and voltmeter.
    Ammeter: (3marks)
    Voltmeter. (3marks)
    (ii) What will be the effect on the voltmeter if both switches are closed? (1mark)
    (iii) Give a reason for the answer to 4.c.(ii) (1mark)

    2 Electricity - Questions
    2006-4.
    a. Figure 3 is a circuit diagram.

    (i) Name the components labeled X and Y. (1mark each)


    (ii) Calculate the total resistance in the circuit. (5marks)
    (iii) Calculate the current in the 30Ω resistor. (2marks)
    (iv) Work out the voltage across the 10 Ω resistor. (2marks)

    2005-8.
    b. describe an experiment that could be done to find out if electrical resistance of a wire varies
    directly proportional to its length (11marks)

    2004-4.
    a. Explain why a voltmeter is connected in parallel while an ammeter is connected in series. (4
    marks)
    b. Figure 2 is a diagram of a resistor.

    What is the resistance of the resistor? (3 marks)

    2004-4.
    e.
    (i) Are the headlamps of a motor car connected in series or in parallel? (1 mark)
    (ii) Give a reason for the answer to 4.e(i). (1 mark)

    2 Electricity - Questions
    3. Power and cost of electricity

    2012-2.
    c. Figure 2 is a diagram of an electric circuit.

    (i) What is the function of the part labelled Z? (2marks)


    (ii) State any two advantages of the circuit in Figure 2. (2marks)
    (ii) Which bulb would use more current if both switches were closed? (1mark)
    (iv) Give a reason for the answer in 2.c.(iii). (1marks)
    d. Calculate the power dissipated in an electric heater in which 4A of current flows when connected
    to a 230V supply. (3marks)

    2010-6.
    c. Define “electrical power”. (1 mark)
    d. An electric bulb is marked 240V, 60W.
    (i) What is the meaning of “240V, 60W”? (2 marks)
    (ii) Calculate the heat dissipated by the bulb, in joules, if it operates for 8 minutes. (3 marks)

    2007-4.
    a. A current of 2A flows through an electric heater connected to a voltage supply of 240V. Calculate
    the:
    (i) resistance of the element, (2marks)
    (ii) power displaced by the heater, (2marks)
    (iii) Cost of running the heater for 3 hours if the cost of electrical energy is K5 per kWh. (4marks)

    2006-4.
    b.
    (i) Define “Kilowatt hour” (2marks)
    (ii) The power rating of a television is 150W. How much power in Kilowatt hours will it use if it is on
    for 109 hours? (3marks)
    (iii) If the cost of power is K5.00 per kilowatt hour, that will be the cost of running the television in
    4.d.(ii) for 10 hours per day for 2 days. (4marks)

    2 Electricity - Questions
    2005-8.
    a. 6kW of power is fed to a transmission cable of resistance 3 ohms. Calculate the power wasted in the
    cable if power is transmitted at 300V. (4marks)

    2003-1.
    a. Figure 1 is a diagram of an electric circuit.

    (i) What kind of energy is produced in the 12 resist or as electric current flows though it? (1mark)
    (ii) Calculate the amount of energy produced in the resistor if electric current flows . (3marks)

    2 Electricity - Questions

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