Q14 of 36 Page 1

For question numbers 14, 15 and 16, two statements are given- one labeled Assertion (A) and the other labeled Reason (R). Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below:

Assertion: After white washing the walls, a shiny white finish on walls is obtained after two to three days.


Reason: Calcium Oxide reacts with Carbon dioxide to form Calcium Hydrogen Carbonate which gives shiny white finish.


a) Both A and R are true, and R is correct explanation of the assertion.


b) Both A and R are true, but R is not the correct explanation of the assertion.


c) A is true, but R is false.


d) A is false, but R is true.


c) Assertion is True & Reason is False


Calcium hydroxide reacts slowly with the carbon dioxide in air to form a thin layer of calcium carbonate on the walls. Calcium carbonate is formed after two to three days of white washing and gives a shiny finish to the walls.


More from this chapter

All 36 →
12

Explain how ozone being a deadly poison can still perform an essential function for our environment.

OR


Give reason why a food chain cannot have more than four trophic levels.


 13

State the role of pancreas in digestion of food.

 15

Assertion: Food chain is responsible for the entry of harmful chemicals in our bodies.

Reason: The length and complexity of food chains vary greatly.


a) Both A and R are true, and R is correct explanation of the assertion.


b) Both A and R are true, but R is not the correct explanation of the assertion.


c) A is true, but R is false.


d) A is false, but R is true.


OR


Assertion: Greater number of individuals are present in lower trophic levels.


Reason: The flow of energy is unidirectional.


a) Both A and R are true, and R is correct explanation of the assertion.


b) Both A and R are true, but R is not the correct explanation of the assertion.


c) A is true, but R is false.


d) A is false, but R is true.


 16

Assertion: A geneticist crossed a pea plant having violet flowers with a pea plant with white flowers, he got all violet flowers in the first generation.

Reason: White colour gene is not passed on to the next generation.


a) Both A and R are true, and R is correct explanation of the assertion.


b) Both A and R are true, but R is not the correct explanation of the assertion.


c) A is true, but R is false.


d) A is false, but R is true.