Listening · Academic Talk
The Science of Colour
Listening · Academic Talk
Listening Test
Today's lecture: physics
This task is designed to measure your ability to understand a short academic lecture on a topic taught in a university class.
In this exercise, you'll listen to a short academic talk and then answer multiple-choice questions about what you heard.
- Each question is worth 1 point. There are 4 questions about this talk.
- The talk plays only once — listen carefully.
- After the talk, you'll have 30 seconds per question. The exercise auto-advances when the timer hits zero.
- You can replay the audio and review the transcript only on the result screen.
The Science of Colour
Listen to the talk and answer the questions
Listen to a talk in a physics class
Show transcript
Why is the sky blue and a leaf green? The answer lies in light. What we see as white light is actually a mixture of all colours, each one a wave of a slightly different length. When that light strikes an object, the object absorbs some wavelengths and reflects others, and the colours we see are simply the ones bouncing back. A leaf looks green because its chlorophyll soaks up red and blue light for energy and reflects the green. The blue sky works differently: as sunlight passes through the air, the shorter blue waves scatter off tiny molecules far more than the longer red waves, so blue light reaches our eyes from all directions. At sunset, when light travels through more air, most of the blue is scattered away before it reaches us, leaving the warm reds and oranges we admire.
Question 1
What is white light actually made of?
Show answer
Answer: A mixture of all colours
Question 2
Why does a leaf look green?
Show answer
Answer: It reflects green light
Question 3
Why is the sky blue?
Show answer
Answer: Blue light scatters more than red
Question 4
Why are sunsets red and orange?
Show answer
Answer: Most blue light is scattered away
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