The downward entry of water into the soil is known

Alternating current is converted into direct current by a –

The absolute zero is a temperature at which -

Which of the following cannot be corrected with spectacles?

Which of the following are environment-friendly practices ?

What is the pH of pure water?

What is the work to be done to increase the velocity of a car from 30 km h⁻¹ to 60 km h⁻¹ if the mass of the car is 1500 kg? 

Which of the following is the ratio of Oxygen to Nitrogen in the air?

An element "X", having atomic number 16. gains two electrons to form an anion X. What will be the atomic

number of 'X' in the anion?

A compound that is a white solid which absorbs water vapour from the air is