Misconception of Energy, Energy Transfer & Energy Conversion of Class 8 students.

1. Student Misconception Series – Science (Part 7)

2. Do your Student Learn or Mug up ? Students of all ages seem to have a mind of their own when it comes to responding to any situation or performing any task. As teachers, most of us go back home thinking that our students have understood every concept that we teach them. It is only when we test them that we find that some concepts have not been understood as clearly as they should have been. It is this desire to understand student thinking that prompted us to examine ASSET questions of the past rounds, in Science, examining the most common wrong answers to understand what could have made students select the options they did.

3. Energy, Energy Transfer & Energy Conversion Class 8

5. Why was the Question asked? This question tests if students understand energy conversions occurring in commonly known devices/ processes. 2. What did students answer? Only 40% of students answered the question correctly. A majority of students selected the wrong options A and D. Possible reason for choosing A: Students probably do not know the energy conversion that takes place in a solar panel, or in a candle. They are probably just relating 'heat' and 'light' that is common between the two and are selecting this option. Possible reason for choosing B: Students selecting this option are either making a random guess or are just considering 'electrical energy‘ (which is the final outcome in the case of solar panels) as common to both these devices. Possible reason for choosing D: Students selecting this option do not understand the energy conversion taking place in the two devices – a solar panel and a steam engine. Some of these students might also have ignored the term 'opposite' and are going for this option because of 'heat' which is common to both of them.

6. 3. Learnings Students are expected to know that in a solar panel, light energy is converted to electrical energy. When asked to find out the device in which the opposite conversion takes place, they should be able to eliminate options A and D since electrical energy is not even an input in these 2 devices. Option B can be eliminated if they understand that the final output in a radio is sound. However, as the data indicate, students do not have this understanding. The common wrong answers seem to indicate that they are looking for some pattern or similarity between the two devices. They are selecting options that have one form of energy common to both the devices without going into the details of energy conversion.

7. 4. How do we handle this? • What is energy? • What are the different types of energy? Give examples of different types of energy. • Can energy be changed from one type to another? Answers to these questions should lead to a discussion in which students are able to bring out different changes observed in daily life where energy conversions occur. List down the various types of energy – light, electrical, heat, chemical and mechanical (nuclear energy can be listed down, but might be difficult for this level). Ask students to take one conversion at a time and give an example for that conversion. For example: • Light energy to electrical energy: Solar cell/solar calculator • Light energy to heat energy: Solar heater • Electrical energy to light energy: Bulb Similarly, give examples of devices and ask students to list down the energy conversion taking place in each of them. What they need to understand in such examples is that there is a source of energy in every case and a final output. For example, in case of a radio, the source is electrical energy and the output is sound. So when the electrical energy is supplied, the circuits fire so as to emit sound. Once the change is known, the energy conversion accompanying the change should be easy to figure out. They should also realise that in many processes, energy conversion follows a multistep process. For example, give the example of a steam engine and ask students to list down the energy conversion taking place. They should realise that the source of energy in that case is coal which has energy stored in the chemical form, which on heating is converted to heat energy which is then used to run the machine - mechanical energy (chemical energy to heat energy to mechanical energy).

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