(a)(i) Thermal equilibrium is a condition in which two bodies in contact have no net flow of heat between them. (ii) Fundamental interval is the difference in temperature between the lower fixed point, i.e. temperature of melting ice at standard atmospheric pressure and that upper fixed point, i.e. temperature of steam at standard atmospheric pressure. (b) Uses of hydraulic press are:- -Compressing metal sheets; -Compressing soft materials into bales; -Compressing paper in printing industries; -Lifting of objects. (c) The material used to reset the steel index in the six's maximum and minimum thermometer is magnet. (d)(i) Heat lost by mixture = Heat gained by water + Heat gained by aluminium. M\(_mC_w\Delta \theta_m\) + C\(_a\Delta\theta_a\) 0.3 x C\(_m\) x (85 - 40) = 0.5 x 4200 (40 - 26) + 90 (40 - 26) 13.5 C\(_m\) = 29400 + 1260 C\(_m\) = \(\frac{30660}{13.5}\) = 2271.1 Jkg\(^{-1}\)K\(^{-1}\) (ii) (\(\alpha\)) The bottle losses heat through conduction and convection. (\(\beta\)) Heat exchanger in: Incubation, refriaeration, air-conditioning, sewage treatment, cooling byradiators, generation of electricity, etc.