What is the resistance of the unknown resistor? an expression for the resistance of a wire in terms of its resistivity, length and diameter. The radius of a wire is doubled. What is the effect of this on the resistance of the wire? 2007 Question 9 [Higher Level] Define resistance. Define resistivity. A metre bridge was used to measure the resistance of a sample of nichrome wire. The diagram indicates the readings taken when the metre bridge was balanced. The nichrome wire has a length of 220 mm and a radius of 0.11 mm. Calculate the resistance of the nichrome wire the resistivity of nichrome. Sketch a graph to show the relationship between the temperature and the resistance of the nichrome wire as its temperature is increased. What happens to the resistance of the wire as its temperature falls below 0oC? What happens to the resistance of the wire as its length is increased? What happens to the resistance of the wire if its diameter is increased? Name another device, apart from a metre bridge, that can be used to measure resistance. Give one advantage and one disadvantage of using this device instead of a metre bridge. Solutions to ordinary Level maths questions 2013 Question 9 (b) [Ordinary Level] State law. Ohm’s The current through a conductor is directly proportional to the voltage Calculate the total resistance of the circuit. 6 + 12 = 18 Ω the current in the circuit. I = = 0.166 A Calculate the potential difference across the 6 resistor. Ω = = (0.166)(6) = 1 V V IR Name an instrument used to measure potential difference. voltmeter 2013 Question 12 (d) [Ordinary Level] State law. Ohm’s Law states that the current flowing through a conductor is directly proportional to the potential Ohm’s difference across it, assuming constant temperature.
What is the resistance of the unknown resistor? an expression for the resistance of a wire in terms of its resistivity, length and diameter. The radius of a wire is doubled. What is the effect of this on the resistance of the wire? 2007 Question 9 [Higher Level] Define resistance. Define resistivity. A metre bridge was used to measure the resistance of a sample of nichrome wire. The diagram indicates the readings taken when the metre bridge was balanced. The nichrome wire has a length of 220 mm and a radius of 0.11 mm. Calculate the resistance of the nichrome wire the resistivity of nichrome. Sketch a graph to show the relationship between the temperature and the resistance of the nichrome wire as its temperature is increased. What happens to the resistance of the wire as its temperature falls below 0oC? What happens to the resistance of the wire as its length is increased? What happens to the resistance of the wire if its diameter is increased? Name another device, apart from a metre bridge, that can be used to measure resistance. Give one advantage and one disadvantage of using this device instead of a metre bridge. Solutions to ordinary Level maths questions 2013 Question 9 (b) [Ordinary Level] State Ohm’s law. The current through a conductor is directly proportional to the voltage Calculate the total resistance of the circuit. 6 + 12 = 18 Ω the current in the circuit. I = = 0.166 A Calculate the potential difference across the 6 Ω resistor. V = IR = (0.166)(6) = 1 V Name an instrument used to measure potential difference. voltmeter 2013 Question 12 (d) [Ordinary Level] State Ohm’s law. Ohm’s Law states that the current flowing through a conductor is directly proportional to the potential difference across it, assuming constant temperature.
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