Sawaal
20
Q:

Directions : For the Assertion (A) and Reason (R) below, choose the correct alternative 

Assertion(A)  : Graphite is slippery and used as a lubricant. 

Reason (R)    : Graphite has free electrons. 

A) Both A and R are true and R is the correct explanation of A. B) Both A and R are true but R is NOT the correct explanation of A.
C) A is true but R is false. D) A is false but R is true.

Answer:   B) Both A and R are true but R is NOT the correct explanation of A.



Explanation:

Graphite possesses a layer structure with two successive layers held by weak forces and able to slide over one another. So, graphite is slippery and this property finds its use as a lubricant. In graphite, each carbon atom is linked to three other carbon atoms while one electron in the carbon atom is delocalised. So, graphite has free electrons 

 

 

Subject: Assertion and Reason
Related Questions
Q:

Directions : For the Assertion (A) and Reason (R) below, choose the correct alternative 

Assertion (A)  : Shivaji developed the guerilla warfare. 

 Reason (R)    : Shivaji feared the Mughals. 

A) Both A and R are true and R is the correct explanation of A. B) Both A and R are true but R is NOT the correct explanation of A.
C) A is true but R is false. D) A is false but R is true.
 
Answer & Explanation Answer: C) A is true but R is false.

Explanation:

 Shivaji initiated the guerilla warfare to defeat the Mughuls but he did not fear them. 

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6 9202
Q:

Directions : For the Assertion (A) and Reason (R) below, choose the correct alternative 

Assertion (A) : There is no vaccine for AIDS. 

 Resson (R)   : The AIDS virus changes its genetic code 

A) Both A and R are true and R is the correct explanation of A. B) Both A and R are true but R is NOT the correct explanation of A.
C) A is true but R is false. D) A is false but R is true.
 
Answer & Explanation Answer: A) Both A and R are true and R is the correct explanation of A.

Explanation:

A vaccine contains the inactivated germs of the disease. But the AIDS virus changes its genetic code and so on vaccine has been invented for it. 

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9 9746
Q:

Directions : For the Assertion (A) and Reason (R) below, choose the correct alternative 

Assertion (A) :  Glass tumbler breaks in winter when hot water is poured in it.

Reason (R)    :  When hot water is poured. the outer surface of glass expands.

A) Both A and R are true and R is the correct explanation of A. B) Both A and R are true but R is NOT the correct explanation of A.
C) A is true but R is false. D) A is false but R is true.
 
Answer & Explanation Answer: C) A is true but R is false.

Explanation:

When in winter, hot water is poured in the glass tumbler. its inner surface tends to expand while the Outer surface in contact with cold atmosphere does not. This opposite interaction causes the tumbler to break. 

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6 9899
Q:

Directions : For the Assertion (A) and Reason (R) below, choose the correct alternative 

Assertion (A)  : In India, females have higher life expectancy than the males. 

Reason (R)    : Females receive a better diet. 

A) Both A and R are true and R is the correct explanation of A. B) Both A and R are true but R is NOT the correct explanation of A.
C) A is true but R is false. D) Both A and R are false.
 
Answer & Explanation Answer: D) Both A and R are false.

Explanation:

In India, due to high birth rate and due to neglect, females have a lower life expectancy than the males and although females need a better diet, they do not receive it. 

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4 9388
Q:

Directions : For the Assertion (A) and Reason (R) below, choose the correct alternative 

Assertion (A) : a Vaccines prevent diseases. 

Reason (R)    : Vaccines must be given to children. 

A) Both A and R are true and R is the correct explanation of A. B) Both A and R are true but R is NOT the correct explanation of A.
C) A is true but R is false. D) A is false but R is true.
 
Answer & Explanation Answer: B) Both A and R are true but R is NOT the correct explanation of A.

Explanation:

Vaccines prevent diseases by developing immunity inside the body and vaccines must be given to children to build in them a resistance against diseases. 

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5 8939
Q:

Directions : For the Assertion (A) and Reason (R) below, choose the correct alternative 

Assertion (A) : Silver is not used to make electric wires. 

Reason (R)   :  Silver is a bad conductor. 

A) Both A and R are true and R is the correct explanation of A. B) Both A and R are true but R is NOT the correct explanation of A.
C) A is true but R is false. D) A is false but R is true.
 
Answer & Explanation Answer: C) A is true but R is false.

Explanation:

Silver is a good conductor of electricity but it is not used to make electric wires because it is expensive 

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Filed Under: Assertion and Reason

10 10837
Q:

Directions : For the Assertion (A) and Reason (R) below, choose the correct alternative 

Assertion (A)  : Legumes revive the soil fertility. 

Reason (R)    : Microbes in the root nodules of legumes fix the atmospheric nitrogen. 

A) Both A and R are true and R is the correct explanation of A. B) Both A and R are true but R is NOT the correct explanation of A.
C) A is true but R is false. D) A is false but R is true.
 
Answer & Explanation Answer: A) Both A and R are true and R is the correct explanation of A.

Explanation:

The root nodules of leguminous plants contain certain nitrogen fixing bacteria which absorb the atmospheric nitrogen and convert it into nitrogeneous compounds useful for the plants reviving soil fertility. 

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Filed Under: Assertion and Reason

11 10858
Q:

Directions : For the Assertion (A) and Reason (R) below, choose the correct alternative 

Assertion (A) : Inside the earth metals are present in molten state. 

Reason (R)   : Earth absorbs the sun's rays. 

A) Both A and R are true and R is the correct explanation of A. B) Both A and R are true but R is NOT the correct explanation of A.
C) A is true but R is false. D) A is false but R is true.
 
Answer & Explanation Answer: C) A is true but R is false.

Explanation:

Inside the earth, the high temperature and pressure keeps the metals in molten state. The earth does not absorb the sun's rays but reflects them. 

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3 8873