Questions

Passivity of iron is due to formation of an extremely thin and impervious film of ferrosoferric oxide Fe3O4on the surface of iron. Chromic acid, being a powerful oxidising agent (like nitric acid ) renders iron passive. 

The Participative leadership style is characterized by 1) allowing a great deal of freedom in identifying problems and solutions, 2) working closely with subordinates, 3) allows extensive participation, but 4) reserving to him/herself the final decision. The consultative style is not so open, with discussion more focused around the leader’s uncertainties than asking for new ideas.

DNA replication is the biological process of producing two identical replicas of DNA from one original DNA molecule. DNA replication occurs in all living organisms acting as the basis for biological inheritance. Complementary base pairing helps prevent errors in DNA replication.

There are 60 minutes in an hour.

In ¾ of an hour there are (60 × ¾) minutes = 45 minutes.

In ¾ of an hour there are (60 × 45) seconds = 2700 seconds.

Siren sounds for every 5 seconds.

In 2700 seconds = 2700/5 = 540 times.

The count start after the first sound, the Siren will sound 541 times in ¾ of an hour.

State-run NTPC said the company has forayed into electric vehicle charging business and has set up first such charging stations at its offices in Delhi and Noida. Adding that the move will push demand for electric vehicles, an official said, "The main objective in setting up the charging points is to be part of promoting clean energy transportation."