GCE O-Level (Singapore) Physics — practice by topic

1. Temperature is literally defined as what is measured on a thermometer. 2. Heat is a transfer of energy due to a temperature difference, so heat energy inside a body is a distinct quantity from a temperature reading. 3. Force between molecules and gas pressure are separate mechanical quantities that a thermometer does not read. 4. So the thermometer reading is the correct definition. _Source: OpenStax Physics (CC BY 4.0), Ch 11 "Thermal Energy, Heat, and Work", section 11.1 Temperature and Thermal Energy_

1. Thermal energy is defined as the average kinetic energy of the particles, molecules or atoms, making up a substance. 2. Potential energy between particles contributes to internal energy but is not what thermal energy measures. 3. Thermal energy is an average across all particles, not the peak kinetic energy of a single particle. 4. Particle mass on its own says nothing about motion, so it cannot define thermal energy. 5. The average kinetic energy description is therefore correct. _Source: OpenStax Physics (CC BY 4.0), Ch 11 "Thermal Energy, Heat, and Work", section 11.1 Temperature and Thermal Energy_

1. The Celsius scale is a relative scale built around a chosen reference point. 2. That reference point is the freezing point of water, fixed at zero degrees. 3. Mercury's boiling point and human body temperature are separate facts about temperature but neither serves as the Celsius reference point. 4. So the freezing point of water is correct. _Source: OpenStax Physics (CC BY 4.0), Ch 11 "Thermal Energy, Heat, and Work", section 11.1 Temperature and Thermal Energy_