Question
The spectrum of white light is made up of seven colours.
(a) Fig. 7.1 shows a partially-completed spectrum. Two labels are missing.
violet | indigo |
| green |
| orange | red |
Fig. 7.1
(i) On Fig. 7.1, write the name of the missing colour in each blank space.
(ii) On Fig. 7.1, indicate the direction of increasing wavelength for the spectrum. Draw an arrow in the box below the spectrum of colours.
(b) A ray of red light strikes one face of a triangular glass prism as shown in Fig. 7.2.
(i) On Fig. 7.2, draw the path of the ray as it travels through the glass prism and enters the air.
(ii) State the term used to describe what happens to the ray of red light as it enters and leaves the prism.
………………………………………………………………………………………………………………………
Answer/Explanation
Answer:
(a)(i) blue between indigo and green
yellow between green and orange
(ii) arrow pointing right →
(b)(i) ray(s) refracted down at first boundary (air/glass)
correct refraction for candidate’s ray (in glass prism)
(ii) refraction
Question
A narrow beam of white light enters a glass prism and splits into the colours of the visible spectrum,
as shown in Fig. 7.1.
(a) The rays leaving the prism represent the seven main colours of the visible spectrum.
Complete the labelling on Fig. 7.1 by writing the colours of the visible spectrum in the table. [2]
(b) State the term used to describe:
the bending of the light as it enters the prism……………………………………………………………………………………………………………………. [1]
the different amounts of bending that produce the spectrum…………………………………………………………………………………………………………………….. [1]
(c) A student incorrectly writes some sentences about electromagnetic waves. His teacher circles a mistake in each sentence.
In the table, write a suitable correction for each mistake. The first one has been done for you.
[2] [Total: 6]
Answer/Explanation
Ans: (a)any 6 correct colours from: red, orange, yellow, green, blue, indigo, violet M1 candidate’s colours in correct order
(b)(i) refraction
(b)(ii) dispersion
(c) infrared (rays/waves) (are used in tv remote controllers) gamma (rays/waves)
- (have the highest frequencies in em spectrum)