Question

1. The focal length of a symthetical conveying lens is equal to the raints of
Then the refractive index is
A) 1
2. After white washing of house, walls will appear to be trighet her to buy the White
substance formed on the walls is
A) Cao
B) HO
C) Culot DYCH
3. When a honey bee stings and injected ethnele acid, what is used to get relief
C) Cotton sale
by Suda Wanel
A) Calcium hydroxide
B) Letron water
4
If"-D" power lens is used for the correction of the eye detect, then the tens used 16
A) Bi convex lens
C) Concave convex lens
B) Plano concave letis
D) concave lens​

Answer 1

Explanation:

Because of the formation of CaCO

3

A solution of slaked lime (Ca(OH)

2

) is used to white wash the walls. Calcium hydroxide reacts with the carbon dioxide in air to form thin layer of calcium carbonate on the walls. It gives a shiny finish to the walls.

Hence option B is correct answer.