Questions

Resistivity :

Resistivity is a measure of the resistance to the flow of electrons. 

Conductivity :

Conductivity is just the inverse of resistivity, σ = 1/ρ, where σ is conductivity and ρ is resistivity.

Example:

Think of a pipe and water, the bigger the pipe, the easier water can flow and thus the lower the resistance. 

Wavelength of a wave can be measured with the distance between two nearest crest and crest or nearest troughs. It is measured as armstrong units.

Dots per inch (DPI, or dpi) is a measure of spatial printing or video or image scanner dot density, in particular the number of individual dots that can be placed in a line within the span of 1 inch (2.54 cm).

The design plans for the U-shaped skyscraper ‘The Big Bend’ in New York, hailed as the world’s longest building, have been revealed. The 4,000-foot long building will feature an elevator system that can travel in curves, horizontally and in loops.

The resistivity of wire or the metal conductor is depend on the number density of free electrons in the conductor. so its mainly depends on nature of the material

Exchange Traded Funds (ETFs) are a relatively new phenomenon and are gaining popularity rapidly. This post outlines the key features of an ETF.

ETFs are like mutual funds because they hold an underlying asset like stocks, debt, commodities future contracts etc. If you are new to the concept of an ETF, think of it as a mutual fund, and build your understanding from thereon. An example of an ETF is the SBI Gold ETF, which holds physical gold as its underlying asset.