Questions

What is main root of plants called as?

What is the ratio of masses of hydrogen and oxygen in the water?

When iron is exposed to moist air, a reddish brown coating of hydrated Iron (III) Oxide (Fe2O3) is deposited on its surface. This reddish brown coating is called

In the following question, out of the four alternatives, select the alternative which is the best substitute of the phrase.
An old unmarried woman

In the following question, the sentence given with blank to be filled in with an appropriate word. Select the correct alternative out of the four and indicate it by selecting the appropriate option.
My sister unlike my brothers __________ to have a career in Engineering.

The percentage change of a number when it is first decreased by 10% and then increased by 10% is

If sec -7π/4 = x, then the value of x is

Piano was invented by ________.