The inductive reactance of a coil is 1000W. If its self inductance and...
We know that,
XL= ωL
Or, XL =2πfL [ ω can be written as, 2πf]
Initially,
XL1=2πf1L1=1000Ω
For the second case,
F and L both are doubled, so,
XL2 =2π2f12L1 =4x2πf1L1
=4000 Ω
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The inductive reactance of a coil is 1000W. If its self inductance and...
Inductive Reactance (Xl) is the opposition that an inductor offers to the flow of alternating current (AC). It is directly proportional to the frequency (f) and the self-inductance (L) of the coil, according to the formula Xl = 2πfL.
Given that the inductive reactance of the coil is 1000W, we can use the formula to find the values of frequency and self-inductance. Let's assume the initial values of frequency and self-inductance as f1 and L1 respectively.
Xl = 2πf1L1
1000 = 2πf1L1
Increase in Frequency
If the frequency is increased two times, the new frequency will be 2f1.
Xl' = 2π(2f1)L1
= 4πf1L1
Increase in Self-Inductance
If the self-inductance is increased two times, the new self-inductance will be 2L1.
Xl'' = 2πf1(2L1)
= 4πf1L1
Combining the two increases:
If both the frequency and self-inductance are increased two times, the new inductive reactance (Xl'') will be:
Xl'' = 4πf1(2L1)
= 8πf1L1
= 8 * 1000
= 8000W
However, the correct answer given is 4000W, not 8000W. Hence, the correct option should be 'C' 4000W.
It seems there might have been an error in the answer options provided, as the increase in self-inductance and frequency by two times would result in an inductive reactance of 4000W, not 16000W.