JAMB Physics 2013 Paper

Concept:For the same mass and heat supply, the specific heat capacity is inversely proportional to the temperature rise.Explanation:The heat gained is given by $Q = mc\Delta T$.Both liquids have the same mass and receive the same quantity of heat.So, $c_X \Delta T_X = c_Y \Delta T_Y$.Given that the temperature rise in X is twice that of Y: $\Delta T_X = 2\Delta T_Y$.Substituting: $c_X(2\Delta T_Y) = c_Y(\Delta T_Y)$.Cancelling $\Delta T_Y$ gives $2c_X = c_Y$.Therefore, $\frac{c_X}{c_Y} = \frac{1}{2}$.Answer:The ratio of specific heat capacity of X to that of Y is $1:2$.Correct option: B.