The area of a semi-circle of radius 7 c.m. is

The oxidation of SO₃^2- to SO₄^2- ion by oxygen
in this reaction which is Lewis acid and Lewis base?

Cyanide resistant respiration is found in

Male sex hormone testosterone is produced by

Which one of the following is correctly matched?

Tax is charged on some items which are manufactured in the country. This is collected by the Government of India. This Tax is

The value of $\dfrac{x^{2}-2x}{x^{2}+2x}$ X $\dfrac{3x+6}{x-2} $

A boy is now twice as old as his sister, four years ago, he was thrice as old as her what are their ages now?

x^3/2 : 9 = 16: $\sqrt{x}$. What is the value of x ?

Total surface area of hollow hemisphere is equal to