Questions

The flow of thermal energy due to differences in their temperatures is called Heat.

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.

I am black gold i.e charcoal. It is black when it is not used and when using it is red due to fire and when used it is in grey color as it becomes ash. 

Memory refresh is the process of periodically reading information from an area of computer memory and immediately rewriting the read information to the same area without modification, for the purpose of preserving the information.

Memory refresh is a background maintenance process required during the operation of semiconductor dynamic random-access memory (DRAM), the most widely used type of computer memory.

Light travels fastest in Vacuum. The fastest thing in the whole universe is the speed of light in a vacuum like outer space. It is about 2.99 x 10⁸ m/s. 

The best example for somatic mutation would be cancer, familial cancer (which transmits through gametes to the next generation) are not so common while sporadic cancer is seen the most where body cells of a particular area goes through mutations for a number of years and becomes cancerous, but it is not transmitted to next generation.