Questions

In the following question, out of the four alternatives, select the alternative which best expresses the meaning of the idiom/phrase.

at the drop of a hat

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

A substance that has no therapeutic effect, used as a control in testing new drugs.

Which of the following is essential for the synthesis of thyroxin?

Give an example of a salt which gives an aqueous solution of pH less than 7.

Chemical formula for sulphurous acid is:

A solution that is at equilibrium must be

Which of the following phrases (i), (ii), and (iii) given below each sentence should replace the phrase printed in bold letters to make the sentence grammatically correct? Choose the best option among the five given alternatives that reflect the correct use of phrase in the context of the grammatically correct sentence. If the sentence is correct as it is, mark (E) i.e., "No correction required" as the answer.
The trees shed his leaves every time autumn approaches but a healthy tree always gets its leaves back in the spring, which explains the point that fighting spirit is enough to keep one afloat.
i. Has shed their leaves every time autumn approaches
ii. shed their leaves every time autumn approaches
iii. shed its leaves every time autumn approaches

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