Assertion and Reason Practice Questions

5 questions per page • Detailed step-by-step solutions

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Question 1
Medium
In a purely inductive alternating current (AC) circuit, current leads the alternating voltage by a phase angle of 90 degrees.|The induced back-electromotive force in an inductor opposes any change in circuit current in accordance with Lenz's Law.
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.
E Both (A) and (R) are false.
Correct Answer: D

Explanation:

Assertion (A) is false; in a pure inductor, voltage leads current by 90° (current LAGS voltage by 90°, remembered by mnemonic 'ELI the ICE man'). Reason (R) is true; back EMF e = -L(di/dt) continually opposes rate of current change as defined by Faraday and Lenz. With (A) false and (R) true, option D is correct.
Question 2
Hard
Liquid helium exhibits super-fluidity and climbs container walls when cooled below 2.17 Kelvin.|Helium was first liquefied by Heike Kamerlingh Onnes in 1908.
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.
E Both (A) and (R) are false.
Correct Answer: B

Explanation:

Assertion (A) is true; Helium II exhibits rollin film flow and zero resistance through capillaries. Reason (R) is true; Onnes liquefied helium at Leiden in 1908, reaching about 4.2 K. Liquefaction history does not explain superfluidity below 2.17 K, which arises from Bose–Einstein condensation of He-4; option B.
Question 3
Medium
The Governor of an Indian State can reserve a bill passed by the state legislature for the consideration of the President, but the President cannot withhold assent to such a reserved bill.|Article 201 provides that the President may either declare assent or declare that assent is withheld, or direct the Governor to return the bill to the legislature.
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.
E Both (A) and (R) are false.
Correct Answer: D

Explanation:

Assertion (A) is false; the President holds absolute veto over state bills and CAN withhold assent indefinitely without time limit. Reason (R) is true; Article 201 explicitly outlines these three distinct courses of presidential action. With (A) false and (R) true, option D is correct.
Question 4
Easy
The Morley-Minto Reforms of 1909 were praised by Indian nationalists as a satisfactory step toward responsible self-government.|The 1909 Indian Councils Act granted non-official majorities in the Central Legislative Council and transferred defense powers to Indian hands.
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.
E Both (A) and (R) are false.
Correct Answer: E

Explanation:

Assertion (A) is false; nationalists bitterly condemned the 1909 reforms for introducing separate electorates and offering no real political power. Reason (R) is false; the Central Council retained an official British majority, and defense was never transferred. Both (A) and (R) are false, so option E is correct.
Question 5
Easy
Diesel engines need spark plugs to ignite the fuel-air mixture.|Diesel engines run on low compression ratios of about 6:1 to 8:1.
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.
E Both (A) and (R) are false.
Correct Answer: E

Explanation:

Assertion (A) is false; diesel engines are compression-ignition engines and have no spark plugs. Reason (R) is false; diesels use high compression ratios of about 14:1 to 22:1, while 6:1 to 8:1 is typical of older petrol engines. Both statements describe a petrol engine rather than a diesel, so option E is correct.
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