The components of the electromagnetic spectrum have different uses. Microwaves are used in cooking and ultraviolet rays are used in sterilisation.

1. (a)Draw one line from each component of the spectrum to another suitable use for that component. component microwaves ultraviolet use sunbeds television controller satellite television airport security check of cases[2]
2. (b)(i)Fig. 5.1 shows a microwave oven used to heat soup. The container for the soup is a glass bowl. Microwaves created inside the oven are reflected by the metal walls. [Figure 5.1] Explain why the choice of material for the container is important in microwave cooking.[1]
3. (b)(ii)The soup is mostly water. Microwaves are completely absorbed by a few centimetres of water. As a result, microwaves do not reach the centre of the soup. The instructions suggest that, after the microwave oven is turned off, the soup: • is not stirred • is left for some minutes so that the centre becomes hot. State the name of and describe each of the two processes by which thermal energy transfers throughout the soup after the microwave oven is turned off. name of first process description name of second process description[3]

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