An inductor coil, a capacitor and an a.c. source of rms voltage 24 V are connected in series. When the frequency of the source is varied, a maximum rms current of 6A is obtained. The inductor coil is then connected to a battery of emf 12 V and internal resistance of `2 Omega`. what will be the circuit?

Options

A. 1.5 A
B. `2 A`
C. `2.5 A`
D. `3 A`

Answer

B

Explanation

The inductor coil has some resistance (R). For a series L, C. R a.c. circuit , the maximum current flows at resonance.
` :. I_(0) = V/R = 24/R :. R = 24/(I_0) = 24/6 = 4 Omega`
This is the resistance of the coil.
When it is connected to a D.C. source, the current supplied by the battery
`:. I = (E)/(R +r) = (12)/(4+2) = 2A`.