GCSE Questions - Electromagnetic Spectrum

Q13.

(a) There are different groups of waves in the electromagnetic spectrum. The diagram below shows the position of three groups of the waves.

Which letter shows the position of infrared? B

[1 mark]

(b) Lex investigated how the colour of a box's surface affects the amount of infrared the box surface absorbs.

Here is the equipment Lex used to investigate this:

There are three types of variable:

the dependent variable, the independent variable and the control variable.

(i) What type of variable in this investigation is the distance between each flask and the infrared heater? control variable

Lex wrote the hypothesis:

'The surface colour of the flask affects the amount of infrared absorbed when the heater is switched on for five minutes.'

(ii) Describe how the equipment shown in the diagram above could be used to test this hypothesis.

Record the initial temperature of the two thermometers in each flask and ensure the initial temperature is the same in both flasks - as it is a control variable.

Switch the infrared heater on, and start the stop clock (at the same time).

After five minutes record the (final) temperature from both flasks and calculate the temperature increase/change.

See / check if the temperature inside the flasks had increased by different amounts.

[4 marks]

(c) Here is a table of Lex's results:

 

Colour of flask
Temperature increase in °C
Test 1
Test 2
Test 3
Black
19
17
27
Silver
10
12
11

 

(i) Which one of the results for the black flask is anomalous? 27 oC

[1 mark]

(ii) The anomalous result was caused by reading the thermometer incorrectly. What should the student do with the anomalous result? Ignore it and if possible repeat it.

[1 mark]

(iii) Calculate the mean temperature increase for the silver flask.

10 + 12 + 11 = 33

33/3 = 11 oC

[1 mark]

(iv) Tick to choose from the three options below a sentence that can be used as a conclusion for the experiment.

Both flasks absorbed the same amount of infrared during the five minutes.  
The black flask absorbed the most infrared during the five minutes.
The silver flask absorbed the most infrared during the five minutes.  

[1 mark]

(Total 10 marks)