TASK DEFINITION: In this task, you are given a question and a context passage. You have to answer the question based on the given passage.
PROBLEM: What is a prerequisite for weight to play a factor in conductivity?, Context: While inert gas reduces filament evaporation, it also conducts heat from the filament, thereby cooling the filament and reducing efficiency. At constant pressure and temperature, the thermal conductivity of a gas depends upon the molecular weight of the gas and the cross sectional area of the gas molecules. Higher molecular weight gasses have lower thermal conductivity, because both the molecular weight is higher and also the cross sectional area is higher. Xenon gas improves efficiency because of its high molecular weight, but is also more expensive, so its use is limited to smaller lamps.

SOLUTION: constant pressure and temperature

PROBLEM: What determines the model of forces?, Context: For certain physical scenarios, it is impossible to model forces as being due to gradient of potentials. This is often due to macrophysical considerations that yield forces as arising from a macroscopic statistical average of microstates. For example, friction is caused by the gradients of numerous electrostatic potentials between the atoms, but manifests as a force model that is independent of any macroscale position vector. Nonconservative forces other than friction include other contact forces, tension, compression, and drag. However, for any sufficiently detailed description, all these forces are the results of conservative ones since each of these macroscopic forces are the net results of the gradients of microscopic potentials.

SOLUTION: gradient of potentials

PROBLEM: Which of the following is not a tonality: major, sonata or minor?, Context: Baroque music is characterized by the use of complex tonal counterpoint and the use of a basso continuo, a continuous bass line. Music became more complex in comparison with the songs of earlier periods. The beginnings of the sonata form took shape in the canzona, as did a more formalized notion of theme and variations. The tonalities of major and minor as means for managing dissonance and chromaticism in music took full shape.

SOLUTION:
sonata