Dictionary

action spectrum

n.
1.the efficiency with which electromagnetic radiation produces a photochemical reaction plotted as a function of the wavelength of the radiation

Word of the Day

Daily English Quiz

General English Quiz is daily dose of question and answers to keep your language knowledge conversant.

English Test

English Test question and answers to keep your language knowledge up-to-date.

English Grammar Test

English Grammar Test is an application to help you enhance your English expertise.

Idiom of the Day

give (someone) enough rope and he or she will hang themself

give someone enough time and freedom to do what they want and they will make a mistake or get into trouble and be caught

"Don`t worry about trying to fight him. If you give him enough rope he will hang himself."

My Account / Test History

Fact
The US federal income tax was first enacted in 1862 to support the Union's Civil War effort. It was eliminated in 1872, revived in 1894 then declared unconstitutional by the Supreme Court the following year. In 1913, the 16th Amendment to the Constitution made the income tax a permanent fixture in the US tax system. .. More >>