Q.

In the given figure, an inductor and a resistor are connected in series with a battery of emf E volt. Ea2b J/s represents the maximum rate at which the energy is stored in the magnetic field (inductor). The numerical value of ba will be _________.                            [2023]


Ans.

(25)

E=12LI2

Rate of energy storing =dEdt=LIdIdt

Now we know for an R-L circuit

        I=ER(1-e-RLt)

So  dIdt=ELe-ttRL

        dEdt=E2R(1-e-ttRL)(e-tRL)

Time at which rate of power storing will be maximum, t=LRln2

So  dEdt=E2R(1-12)×12

  E24R=E2100=E22×50

a=2,  b=50

So  ba=25