Question 96: Electromagnetic Induction

Question

An inductor coil stores 64 J of magnetic field energy and dissipates energy at the rate of 640 W when a current of 8A is passed through it. If this coil is joined across an ideal battery, find the time constant of the circuit in seconds :

Accepted Answer

$$U = {1 \over 2}L{i^2} = 64 \Rightarrow L = 2$$
$${i^2}R = 640$$
$$R = {{640} \over {{{(8)}^2}}} = 10$$
$$	au  = {L \over R} = {1 \over 5} = 0.2$$

Answer

0.4

Answer

0.8

Answer

0.125

Answer

0.2

Electromagnetic Induction

An inductor coil stores 64 J of magnetic field energy and dissipates energy at the rate of 640 W when a current of 8A is passed through it. If this coil is joined across an ideal battery, find the time constant of the circuit in seconds :

Choose the correct answer: