# P1.1.3 Energy transfer by heating

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P1.1.3 Energy transfer by heating
P1.1.3 Energy transfer by heating GCSE items that can be used to define successful outcomes for peer and self assessment activities

Using Exam pro items to support successful outcomes
Assessment of practical work Using Exam pro items to support successful outcomes Learners will be able to test their progress against learning outcomes using questions taken from past AQA GCSE questions. Version Copyright © AQA and its licensors. All rights reserved.

Q1 foundation The diagram shows potatoes being baked in a gas oven. Each potato has a metal skewer pushed through it. Version Copyright © AQA and its licensors. All rights reserved.

By what method is heat transferred through a metal skewer? (1)
Q1 contd. (a) Explain how heat is transferred by the process of convection from the gas flame at the bottom of the oven to the potatoes at the top of the oven (3) (b) The metal skewers help the potatoes to cook by transferring heat to the inside of the potatoes. By what method is heat transferred through a metal skewer? (1) (c) When the potatoes are taken from the oven, they start to cool down. Suggest one factor that will affect how fast a potato cools down (1) Version Copyright © AQA and its licensors. All rights reserved.

Q1 mark scheme (a) any three from: ignore reference to skewer
• (air) particles / molecules / atoms gain energy • (air) particles / molecules / atoms move faster do not accept move more, do not accept move with a bigger amplitude / vibrate more • (air) particles / molecules / atoms move apart • air expands do not accept particles expand • air becomes less dense • warm / hot air rises do not accept heat rises 3 (b) Conduction accept conductor (c) any one from: • temperature of the potato do not accept heat for temperature • temperature of the surroundings / room / surface / atmosphere accept how hot the potato / room is • size / mass / weight / volume of the potato • shape of the potato • surface area of the potato potato cut open insufficient • nature of the surface of the potato • type of surface it is placed on • in a draught • type of potato • whether the skewers are left in or taken out 1 Version Copyright © AQA and its licensors. All rights reserved.

Q2 foundation AQA-PH1FP-QP-Jan12 Q7
The diagram shows two thermometers. The bulb of each thermometer is covered with a piece of wet cotton wool. One of the thermometers is placed in the draught from a fan. Version Copyright © AQA and its licensors. All rights reserved.

Q2 contd. The graph shows how the temperature of each thermometer changes with time.

Q2 Contd. (a) Which of the graph lines, A or B, shows the temperature of the thermometer placed in the draught? Explain, in terms of evaporation, the reason for your answer. (3 marks) (b) A wet towel spread out and hung outside on a day without wind dries faster than an identical wet towel left rolled up in a plastic bag. Explain why. (2 marks) Version Copyright © AQA and its licensors. All rights reserved.