For two telescopes observing the same star, the recorded signal is proportional to mirror area multiplied by exposure time. All other conditions are identical. Telescope P has a mirror diameter of 0.50 m and an exposure time of 8.0 min. Telescope Q has a mirror diameter of 1.0 m and an exposure time of 3.0 min. The area of a circular mirror is proportional to the square of its diameter. What is the ratio of the signal recorded by Q to that recorded by P?
0.750.750.75
1.501.501.50
2.002.002.00
6.006.006.00
75 exam-style questions on Edexcel GCSE Physics 7.3 Stars, covering 7.3.1 Evolution of stars similar to the Sun, 7.3.2 Evolution of massive stars, and 7.3.3 Observing the Universe. Each one has a worked solution and a mark scheme showing where the marks go.