Assertion (A) >: In our houses, the current in AC electricity line changes direction 60 times per second. Reason (R) >: The frequency of alternating voltage supplied is 60 hertz.

examrobotsa's picture

Submitted by examrobotsa on

Q: 72 (IAS/2004)

Assertion (A): In our houses, the current in AC electricity line changes direction 60 times per second.
Reason (R): The frequency of alternating voltage supplied is 60 hertz.

question_subject: 

Science

question_exam: 

IAS

stats: 

0,6,45,29,11,5,6

keywords: 

{'ac electricity line': [0, 0, 1, 0], 'frequency': [0, 0, 1, 3], 'hertz': [0, 0, 2, 2], 'current': [0, 0, 0, 3], 'voltage': [0, 0, 0, 1], 'direction': [0, 0, 0, 3]}

Option 1 implies that both the assertion and reason are correct, and that the reason accurately explains the assertion.

Option 2 also indicates that both the assertion and reason are accurate, but the reason does not provide a valid explanation for the assertion.

Option 3 suggests that only the assertion is correct, and the reason is wrong.

Option 4 denotes that the assertion is incorrect while the reason is correct.

The given answer is option 4. This means that the assertion, which states that the AC electricity in our homes changes direction 60 times per second, is false. AC electricity changes direction 50 or 60 times per second depending on the country; in the US it`s 60 times, but in many countries (like most of Europe), it`s 50 times. Meanwhile, the reason, further stating that the frequency of the alternating voltage supplied is 60 hertz, is true. This is because alternating current (AC) frequency in most parts of the world is either 50 Hz or 60 Hz.