Electrical Engineering - Alternating Current and Voltage - Discussion

Discussion Forum : Alternating Current and Voltage - General Questions (Q.No. 19)
19.
Sine wave A has a positive-going zero crossing at 45°. Sine wave B has a positive-going zero crossing at 60°. Which of the following statements is true?
Wave A leads wave B by 15°.
Wave A lags wave B by 15°.
Wave A leads wave B by 105°.
Wave A lags wave B by 105°.
Answer: Option
Explanation:
No answer description is available. Let's discuss.
Discussion:
24 comments Page 2 of 3.

STUTI KUSHWAHA said:   10 years ago
Answer is A. Because if we think with the help of graph then we find that a start from 45 and after 15 means at 60 b will start then it is clear that a is lead with 15.

Jsjjaj said:   9 years ago
Option b is the correct answer.

Rahul said:   9 years ago
Option A is right. Because it crosses zero at the angle of 45 degrees. But B is cross after 60 degrees.

Vino said:   9 years ago
I can't understand it. Please help me.

Sunil Malappuram said:   9 years ago
I think wave B leads. Please give clarification about the answer.

Lovaraju said:   9 years ago
As per my knowledge B is right.

Akshay said:   9 years ago
Option A is right because A reaches to 0 before B at 15 degrees.

Waheed ullah khattak said:   9 years ago
B is the correct option.

Dhaval said:   8 years ago
Answer should be B because lagging and leading does not depend on Cross zero first. It depends upon the angle of the wave. So right answer should be B.
(1)

Abdul Majid said:   7 years ago
Hi all.

Option B is correct. Here is the explanation:

That signal leads which crosses a point before the other signal.
δ _t=∠/360*f.
Where Δ_t=tB-tA.

And ∠ is phase difference given by:
∠=∠B-∠A.

And it should be cleared here if Δ t is +ve then signal A is lagging and Vice versa
In our problem.

∠=60-45=15=+ve so Δ t is also +ve and hence wave A is lagging wave B by 15 degrees.

I hope this helped you.
Thanks


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