Find out the rms value of current in the circuit wherein a 35 mH induc...
To find the rms value of current in the circuit, we need to calculate the impedance of the inductor and then use Ohm's law.
1. Impedance of the Inductor:
The impedance of an inductor (ZL) is given by the formula ZL = jωL, where j is the imaginary unit, ω is the angular frequency, and L is the inductance.
Given:
Inductance (L) = 35 mH = 35 × 10^(-3) H
Angular frequency (ω) = 2πf, where f is the frequency
Substituting the values, we get:
ω = 2π × 70 Hz = 140π rad/s
Now, calculating the impedance of the inductor:
ZL = jωL = j(140π)(35 × 10^(-3)) = j4.9π
2. Ohm's Law:
Ohm's law states that the current (I) flowing through a circuit is equal to the voltage (V) across the circuit divided by the impedance (Z) of the circuit. Mathematically, it can be written as I = V/Z.
Given:
Voltage (V) = 200 V
Substituting the values, we get:
I = 200 V / j4.9π
To find the rms value of current, we need to take the magnitude of the complex current. The magnitude of a complex number a + bj is given by √(a^2 + b^2).
3. Calculating the Magnitude of Current:
We need to convert the expression for current from polar form (j4.9π) to rectangular form. Using Euler's formula, we have j = e^(jπ/2).
I = 200 V / j4.9π
= 200 V / (e^(jπ/2)4.9π)
= 200 V / (e^(jπ/2) × e^(j4.9π))
= 200 V / e^(jπ/2 + j4.9π)
= 200 V / e^(j(π/2 + 4.9π))
= 200 V / e^(j(5.4π))
Taking the magnitude of the current, we have:
|I| = |200 V / e^(j(5.4π))|
= |200 V / (cos(5.4π) + j sin(5.4π))|
= |200 V / (-1 + j0)|
= |200 V / (-1)|
= |-200 V|
= 200 V
Therefore, the rms value of the current in the circuit is 200 A.
The given options are:
a) 13 A
b) 15 A
c) 20 A
d) 45 A
None of the given options match the calculated rms value of 200 A. Hence, the given options are incorrect.
Find out the rms value of current in the circuit wherein a 35 mH induc...
X
L = 2π f L
X
L = 2π × 70 × 35 × 10
-3 Ω.

I
rms = 12.99 A ≈ 13 A
Therefore, the rms value of current in the circuit is 13 A.