Which statement is most accurate? a- the greater the physical density of a material, the higher the refractive index. b- the greater the optical density of the material, the lower the refractive index. c- the more optically dense the material, the higher the refractive index. d- the greater the physical density of a material, the lower the refractive index.

Along wire of diameter 1 mm is submerged in an oil bath of temperature ∞ 31°c. the wire has an electrical resistance per unit length of 0.01 ω/m. if a current of 103 a flows through the wire and the convection coefficient is 500 w/m2·k, what is the steady-state temperature of the wire? from the time the current is applied, how long does it take for the wire to reach a temperature that is within 1°c of the steady-state value? the properties of the wire are 8000 kg/m3, 500 j/kg·k, and 20 w/m·k.