In a cryogenic laboratory, liquid nitrogen is vaporised inside a cooling jacket to cool a superconducting magnet coil from 293 K to 77 K.
Give two reasons why the actual mass of liquid nitrogen required to cool the coil to 77 K is greater than the calculated value of 6.2 kg.
36 exam-style questions on Edexcel GCSE Physics 14.2 Specific heat capacity and latent heat. Each one has a worked solution and a mark scheme showing where the marks go.