When 100V D.C. is applied across a coil, a current of 1A flows through it. When 100V A.C. of 50 Hz is applied to the same coil, only 0.5A flows. The inductance of the coil is :-
Question
When 100V D.C. is applied across a coil, a current of 1A flows through it. When 100V A.C. of 50 Hz is applied to the same coil, only 0.5A flows. The inductance of the coil is :-
Solution
To find the inductance of the coil, we first need to find the reactance (X) of the coil when the AC voltage is applied.
Reactance (X) is the resistance offered by a coil to the flow of AC current. It is given by the formula:
X = V / I
where V is the voltage and I is the current.
In this case, when the AC voltage is applied, V = 100V and I = 0.5A.
So, X = 100 / 0.5 = 200 ohms.
The reactance of a coil is also given by the formula:
X = 2πfL
where f is the frequency and L is the inductance.
In this case, f = 50Hz. We can rearrange the formula to solve for L:
L = X / (2πf)
Substituting the known values:
L = 200 / (2π * 50) = 200 / (100π) = 2 / π Henry
So, the inductance of the coil is 2 / π Henry.
Similar Questions
A coil has resistance 30 ohm and inductive reactance 20 Ohm at 50 Hz frequency. If an ac source, of 200 volt, 100 Hz, is connected across the coil, the current in the coil will be :
The coil of a moving iron instrument has a resistance of 500 Ω and an inductance of 1 H. It reads 250 V when a 250 V dc is applied. If series resistance is 2000 Ω, its reading when fed by 250 V, 50 Hz ac will be
A coil induces 350 mV when the current changes at the rate of 1 A/s. The value of inductance is:a.350mHb.250mHc.150mHd.3,500mH
n a coil of resistance 100 a current is induced by changing the magneticflux through it. The variation of current with time is as shown in the figure. Themagnitude of change in flux through coil is(a) 200 Wb (b) 275 Wb (c) 225 Wb (d) 250 Wb
A square-wave voltage of 100V with frequency of 60Hz is applied on a coilwound on a closed iron core. The coil has 500 turns, and the cross-section areaof the core is 0.001m2. If the core has no resistance, determinea) the maximum value of flux;b) the maximum value of voltage with the maximum flux density of 1.2T
Upgrade your grade with Knowee
Get personalized homework help. Review tough concepts in more detail, or go deeper into your topic by exploring other relevant questions.