Microwaves
3 marks · EasyMicrowaves are widely used in satellite communication and cooking.
State one reason why microwaves are suitable for use in satellite communications.
Explain why metal screens are used in the doors of microwave ovens.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
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(a) Microwaves can pass easily through the Earth's atmosphere.
(b) Metal screens reflect microwaves, keeping them inside the oven and protecting users from harm. · must show mention of reflection/containment, mention of protection from microwaves
Also accept: For part (a), accepts answers referencing microwaves passing easily through the atmosphere.
Common mistakes: Not mentioning protection in part (b).
Show mark scheme and worked solution
Marking points
B1 (a) · 1 mark · States that microwaves can pass easily through the Earth's atmosphere.
B1 (b) · 1 mark · Mentions that metal screens reflect or contain microwaves/keep them inside the oven.
B2 (b) · 1 mark · States that this protects users from harm/detrimental effects.
Worked solution
a) Microwaves are suitable for satellite communications because they can pass easily through the Earth's atmosphere.
b) Metal screens are used in the doors of microwave ovens because they reflect microwaves, keeping them inside the oven. This prevents microwaves from leaking out and protects users from potential harm.