Assertions and Reasons MCQ Quiz - Objective Question with Answer for Assertions and Reasons - Download Free PDF

Assertion (A) When common salt is kept open, it absorbs moisture from the air. → True

This statement is true. Common salt (sodium chloride, NaCl) can absorb moisture from the air, especially in humid conditions. This statement is misleading.

Reason (R) Common salt contains magnesium chloride → True

Although magnesium chloride (MgCl2) is a deliquescent material that absorbs moisture, sodium chloride (NaCl), not magnesium chloride, is the main ingredient in common table salt.  Magnesium chloride is an impurity that can be present in some salt varieties, but it is not a characteristic of regular salt.

Although the statement is true, the justification given is incorrect given that sodium chloride makes up the majority of common salt.  As a result, even though there may be some truth to both claims, the justification is incorrect.

Thus, Both A and R are true and R is the correct explanation of A.

Hence, "Option 1" is the correct answer.

Assertion (A) When common salt is kept open, it absorbs moisture from the air. → True

Reason (R) Common salt contains magnesium chloride → True

Magnesium chloride is common salt is deliquescent and absorbs moisture from the air. Thus the reason (R) is the correct explanation of the assertion (A).

Thus, Both A and R are true and R is the correct explanation of A.

Hence, "Option 1" is the correct answer.

Assertion (A) An iron ball floats on mercury but sinks in water. → True

Reason (R) The specific gravity of iron is more than that of mercury. → False

Iron is denser than water, so it sinks in water. But mercury is denser than iron, so iron floats on mercury.

Thus, (A) is true but (R) is false.

Hence, "Option 3" is the correct answer.

Given:

Assertion (A): COVID-19 is caused by a virus. Antibiotics do not work against viruses.

Reason (R): The bacteria of COVID-19 is very infective.

Explanation:

Assertion (A) is true:

COVID-19 is caused by the SARS-CoV-2 virus, and antibiotics are ineffective against viruses.

Reason (R) is false:

COVID-19 is caused by a virus, not bacteria.

∴ A is true, and R is false.

Hence the correct answer is "Option 4"

Given statement:

Global warming is the unusually rapid increase in Earth's average surface temperature over the past century primarily due to the greenhouse gases released by people.

I: Generating electricity and heat by burning fossil fuels causes a large chunk of global emissions.

Burning fossil fuels (such as coal, oil, and natural gas) releases significant amounts of carbon dioxide (CO₂) and other greenhouse gases into the atmosphere.

This is a major contributor to global warming. 

II: Deforestation contributes to global greenhouse gas emissions. It is responsible for approximately 25% of them.

Trees absorb CO₂, and cutting them down (deforestation) reduces the Earth's ability to absorb CO₂ while also releasing stored carbon into the atmosphere. This significantly contributes to global warming.

Thus, Both I and II are possible reasons.

Hence, the correct answer is "Option 4".

The doctrine of Lapse was adopted as an annexation policy with respect to the expansionist tendencies of the British East India Company.

And according to the policy, if a ruler was incompetent or left without a male heir to the throne, the state was bound to lose its princely status.

So, the assertion is correct.

Also, this policy was widely implemented by Lord Dalhousie, who was the Governor-General of the East India Company in India between 1848 and 1856 but actually the policy was drafted in 1847.

So, the stated reason is correct but does not explain the assertion.

Option(1) is correct.

Assertion: Moon cannot be used as a satellite for communication - True as Moon is very far away from Earth (the orbital time period is approximately 27.3 days), also it does not have an equatorial orbit nor have a polar orbit.

Reason (R): Moon does not move in the equatorial plane of the earth - True and that's why it cannot be used as a satellite for communication.

Hence, the correct answer is Option(1) i.e., Both A and R are true and R is the correct explanation of A.

Assertion (A): Ventilators are provided near the roof. → True

It is true that ventilators are provided near the roof.

Reason (R): Conduction takes place better near the roof. → False

Conduction is the transfer of energy through a medium, from higher energy level to lower energy level.

Hence, A is true but R is false.

Assertion (A):

Methane gas released by some industries leads to global warming. → True

Reason (R):

Methane is a heavy gas and it settles in the lower regions of the atmosphere. → False

Methane is a strong greenhouse gas with a global warming potential 84 times higher than Carbon dioxide. 

Hence, A is true but R is false.

The assertion that all cockroaches are brown is not correct as some species of cockroaches are not brown but, the given reason is correct.

Hence, the given assertion is false but the reason is true.

Since the disease is caused by the Influenza virus, the government needs to control the spread of the virus to stop the spread of the disease which is stated in conclusion II. Hence conclusion II follows. 

There is no information provided in the statement to suggest that the disease is fatal. Therefore, conclusion I cannot be drawn from the given statements and 2 is the right option. 

Forest has been gradually decreased because of increased population. Human cuts the forest and make houses. Many more thing are there to cut trees. Illegal cutting of trees one of the main concerns. So here reason is the best suitable for the given assertion.

The assertion is correct because it is true that rocket science is also built upon the basic concepts of Newton with a complex calculation and numerous possibilities.
Hence, the assertion is true.

But the reason is not correct as it says that anyone can make a rocket on his own which is logically inconsistent.
Therefore, the reason is false.

Hence, A is true, but R is false

Vehicles emit carbon dioxide which is a greenhouse gas.

Therefore, Reason (R) is true.

Therefore, increase in average cars on road means increase in carbon emissions.

Therefore, Assertion(A) is true.

Hence, (A) is true and (R) is true and (R) is the correct explanation of (A).

It is true that black money is a big problem in India and that the prices of goods are increasing rapidly in the country. But the reason is not the complete explanation behind the assertion.