Home
Class 12
PHYSICS
A coil having resistance 15 and inductan...

A coil having resistance 15 and inductance 10 H is connected across a 90 Volt supply. Determine the value of current after 2sec . What is the energy stored in the magnetic field at that instant

Text Solution

Verified by Experts

Given that `R = 15 Omega ,L = 10 H, E = 90` Volt
Peak value of current
`I_0 = E/R = 90/15 A = 6A ` also `tau_L = L/R = 10/15 = 0.67 sec`
Now `I =I_0 (1 - e^((-Rt)/(L)) )` , after 2 sec
`I = 6 [1-e^(-2//0.67) ] = 6[1-0.05] = 5.7A`
Energy stored in the magnetic field
`U = 1/2 LI^2 = 1/2 xx 10 xx (5.7)^2 J = 162.45J`
Promotional Banner

Topper's Solved these Questions

  • ELECTROMAGNETIC INDUCTION

    AAKASH SERIES|Exercise EXERCISE-IA|58 Videos

  • ELECTROMAGNETIC INDUCTION

    AAKASH SERIES|Exercise EXERCISE-IB|18 Videos

  • ELECTRIC FIELD AND POTENTIAL

    AAKASH SERIES|Exercise PROBLEMS (LEVEL-II)|26 Videos

  • ELECTROMAGNETIC WAVES

    AAKASH SERIES|Exercise EXERCISE -II|22 Videos

Similar Questions

Explore conceptually related problems

A coil of resistance 10Omega and an inductance 5H is connected to a 100 volt battery. Then energy stored in the coil is

A coil of inductance 1.0 H and resistance 100 Omega is connected to a battery of emf 12 V. Find the energy stored in the magnetic field associated with the coil at an instant 10 ms after the circuit is switched on.

A coil of resistance 20Omega and inductance 0.5H is switched to DC200V supply. Calculate the rate of increase of current a. at the instant of closing the switch and b. after one time constant. c. Find the steady state current in the circuit.

A coil of resistance 20Omega and inductance 0.5H is switched to DC200V supply. Calculate the rate of increase of current a. at the instant of closing the switch and b. after one time constant. c. Find the steady state current in the circuit.

An LR series circuit has L=1 H and R=1 Omega .It is connected across an emf of 2 V .The maximum rate at which energy is stored in the magnetic field is:

A coil having an inductance L and a resistance R is connected to a battery of emf epsilon . Find the time elapsed before, the magnetic field energy stored in the circuit reaches half its maximum value.

A coil having a resistance of 50.0 Omega and an inductance of 0.500 henry is connected to an AC source of 110 volts, 50.0 cycle/s. Find the rms value of the current in the circuit.

An inductor coil of resistance 10 Omega and inductance 120 mH is connected across a battery of emf 6 V and internal resistance 2 Omega . Find the charge which flows through the inductor in (a) 10 ms, (b) 20ms and (c ) 100ms after the connections are made.

A coil having inductance 2.0 H and resistance 20 Omega is connected to a battery of emf 4.0 V. Find (a) the current a the instant 0.20 s after the connection Is made and (b) the magnetic energy at this instant.

A coil has an inductance of 50 m H and a resistance of 0.3Omega . If a 12V emf is applied across the coil, the energy stored in the magnetic field after the current has built up of its steady state value is