Questions

90 D in a R A => 90 degrees in a Right Angle. 

This is similar to 

26 L of the A = 26 Letters of the Alphabet

12 S of the Z.

Yellow and green color mix make a Lime color.

The three primary colors in additive mixing are red, green, and blue. In the absence of color or, when no colors are showing, the result is black. If all three primary colors are showing, the result is white. When red and green combine, the result is yellow. When red and blue combine, the result is magenta. When blue and green combine, the result is cyan.

Hydrogen Bomb is based on the principle of Nuclear Fusion.

• Nuclear fusion is a reaction in which two or more atomic nuclei are combined to form one or more different atomic nuclei and subatomic particles.

• The difference in mass between the reactants and products is manifested as either the release or absorption of energy.

206 Bones in the Human Body.

Here all the given options are Exothermic reactions. Exothermic reactions are those reactions which involves the release of heat.

Generally all the combining reactions are exothermic in nature.