Alternating current (AC) is used in homes because it is safer than direct current (DC).  

A thermos bottle minimizes heat transfer by radiation.

Significant figures are used to express the precision of measurements.

Water expands when heated at all temperatures.

Objects in free fall accelerate at different rates independent of their mass.

A hypothesis is a proven scientific fact.

The speed of sound increases as temperature decreases in air.  

Magnetic fields can exert forces on moving charges.  

The Curie temperature is the temperature below which a material becomes ferromagnetic.  

The refraction of light causes mirages due to frequency.