The distance between two telephone poles is 50 m. An engineer installs a copper communication cable of length 51.5 m between them.
Why does the engineer choose a cable that is longer than the distance between the two poles?
to allow for contraction of the cable in cold weather
to speed up the transmission of electrical signals
to decrease the strength of the electric current
to create a downward slope so that electric charge can flow more easily
96 exam-style questions on CIE IGCSE Physics 2.2.1 Thermal expansion of solids, liquids and gases. Each one has a worked solution and a mark scheme showing where the marks go.