The milkman shifts the pH of the fresh milk from 6 to slightly alkaline (to decrease the rate of fermentation) because in alkaline condition milk does not set as curd easily.

Magnification obtained by a lens is the ratio of height of image (h₁) to the height of object (h₂) i.e., Magnification, m= h₁/h₂

When we cut sphere, two parts we got and here spherical mirror is formed. But remember, applying silvering colour or agent either the inside or outside surface.

(i) Pb + CuCl₂ → PbCI₂ + Cu (ii) Na₂SO₄ + BaCl₂ → BaSO₄ + 2NACI (iii) C+ O₂ → CO₂ (iv) CH₄ + 20₂ → CO₂ + 2H₂ O

(I) Displaces silver from the solution (II) Forms a blue coloured complex with AgNO₃ (III) Is oxidized to Cu2⁺ (IV) Is reduced to Cu2⁺

When white light enters a Prism, different colours undergo refraction and as they enter a denser medium, they bend towards the normal at different angles.

The colours in ascending order of wavelength are: Violet, Indigo, Blue, after that Green, Yellow, Orange and lastly, Red. The wavelength of violet colour is the least (First stand in wavelength) and that of red (last stand in wave length) ...

In the year 1670, Dutch biologist Anton van Leeuwenhoek discovered the living cell when he looked at pond water under a microscope, which is made up of lenses.

Class 9th Science Session 2021-22 Class 9 Science Terminal Exams MCQ Solutions Class IX Science MCQ Extra Questions Answers 9th Science Terminal Exam Based MCQ Extra Questions