Which statement is FALSE?

a) planetary nebulae can have layers because of pulsating stars
b) planetary nebulae usually last tens of thousands of years
c) a planetary nebula will be part of the end state of the Sun
d) planetary nebulae usually have black holes at their centers
e) planetary nebulae are a few light years in size

Which situation will have the highest resistance? a.long wire and high temperatureb.short wire and high temperaturec.long wire and cold temperaturedshort wire and low temperature

Antireflective coatings on solar cells are often made by applying a thin film of silicon nitride (sinx), which has an index of refractive of 1.2, on the top of the silicon solar cell, which has a refractive index of about 3.5. however, the sun emits radiation of various wavelengths which the solar cell absorbs, and the antireflective coating can only absolutely minimize the reflection of one of these wavelengths. the coating thickness is chosen to reduce the reflection of green/yellow light (e = 2.2 ev), which is the most intense color in the solar spectrum (shown below). which of the following coatings would minimize reflection of green/yellow light? the answer is 820 nm how? what is the angular width of the central maximum of an electron traveling at 2 x 108 m/s going through a single slit of width 1 mm.

Tara goes on a camel safari in africa. she travels 5 km north, then 3 km east and then 1 km north again. what distance did she cover? what was her displacement?