Assertion and Reason Questions and Answers

Answer: A

The answer is Both (A) and (R) are true, but (R) is not the correct explanation of (A).

The Assertion is true: Earth is the only planet on which life is known to exist. The Reason is also true: Earth's atmosphere is a mixture of gases, mainly nitrogen and oxygen with argon, carbon dioxide and others.

But having an atmosphere that is a mixture of gases does not explain why Earth has life. Venus and Mars also have atmospheres of mixed gases and no known life. Life depends on a combination of factors, such as liquid water, a suitable temperature range, free oxygen and protection from radiation. So the Reason does not explain the Assertion.

Answer: C

The key treats A as true and R as false. The assertion is a settled feature of the Constitution: the judiciary is independent of the executive, with security of tenure for judges and separation of the appointment and removal procedures from ordinary executive control. The reason says the judiciary has no interference in the affairs of the state and cannot be influenced by the government. The key counts this as false, because the courts do review the actions of the state and the government and can strike them down, and because the executive has a part in appointments. The wording of R is loose, so the question depends on the key. The options that call R true, or A false, do not agree with it.

Answer: C

R is true but A is false. India became independent on 15 August 1947, not on 26 January, so the assertion is false. The Republic Day, on which the Constitution came into force, is celebrated on 26 January (since 1950), so the reason is a true statement even though it does not support the assertion. So 'R is true but A is false' is correct. The options saying both are true are wrong because A is false, and the option saying both are false is wrong because R is true.

Answer: B

Both statements are true, but the reason does not explain the assertion. Silver has the highest electrical conductivity of all metals, so A is true. Wood is an electrical insulator, so R is true. But conductivity of silver depends on its free electrons and metallic bonding. That wood is an insulator says nothing about why silver conducts so well, so R is not the explanation of A.

Options 1, 3 and 4 each treat one statement as false or the link as valid, which is wrong.

Answer: B

The correct option is (A) is false but (R) is true.

The Assertion is false because 2 is a prime number and it is even. All other primes are odd, but 'all prime numbers are odd' has this one exception.

The Reason states the definition of a prime: a number greater than 1 whose only divisors are 1 and itself. That is true. Since the Assertion is false, the options calling both true are wrong, and since the Reason is true, 'Both false' is wrong.

Answer: D

The answer is A is not correct but R is correct.

The Assertion is false. A fable is a short story, usually with animals behaving like people, that teaches a moral, as in Aesop's fables or the Panchatantra. A fairytale is a story of magic, fairies, witches and enchanted kingdoms, which need not teach a moral. Some stories share features, but not all fairytales are fables.

The Reason is true: fables commonly have animal characters, such as the fox and the crow or the tortoise and the hare.

Answer: C

Correct answer: A is true but R is false.

Pressure-cooker handles really are made of ebonite, so A is true. But the reason is that ebonite is a poor conductor of heat, so the handle stays cool enough to grip - not that it is strong. R is false as a description of the material’s relevant property.

Answer: C

Correct answer: A is true but R is false.

Pluto is indeed the coldest of the bodies traditionally counted as planets, at around \( -230^{\circ}\mathrm{C} \), so A is true. But the cause is its enormous distance from the sun - sunlight there is some 1600 times fainter than at the earth - not the slant of the rays, which is what makes the earth’s poles cold. R is false.

Answer: B

Correct answer: Both A and R are true but R is NOT the correct explanation of A.

Diamond does cut glass and it does have a high refractive index, so both statements are true. But the two have nothing to do with each other: diamond cuts glass because it is the hardest natural substance, while its refractive index is why it sparkles. R does not explain A.

Answer: A

Correct answer: Both A and R are true and R is the correct explanation of A.

Simla is colder than Delhi, and it stands at about 2200 m against Delhi’s 220 m. Air cools by roughly \( 6.5^{\circ}\mathrm{C} \) for every kilometre of ascent, so the altitude difference accounts for the temperature difference directly. Both are true and R explains A.