Name: Polarity Across Inductor in Electric Circuits
Uploaded: 2019-07-19
Duration: 5 min 40 s
Description: This video enables students to understand the inductor, sign conventions and polarity across the inductor in an AC circuit and DC circuit. Click to learn more!

Question

The current in an inductor is given by

i = 5 + 16 t

, where

i

and

t

are in ampere and second respectively. The induced

emf

is

10 mV

. Find out

(i)

self-inductance and

(ii)

the energy stored in the inductor at

t = 1

second.

Accepted Answer

Given that $\frac{di}{dt} = 16 {As}^{- 1}$
The formula to calculate emf across the conductor is:
$ε = |L \frac{di}{dt}|$
From this, the formula used to calculate the self inductance $(L)$ is obtained as

$ε = L \frac{di}{dt}$

We get,

$10 \times 10^{- 3} = L \frac{d}{dt} (5 + 16 t) = L \times 16$

Or $L = \frac{10}{16} \times 10^{- 3} H = 6.25 \times 10^{- 3} H$

So, The self-inductance $= 6.25 \times 10^{- 3} H = 0.625 mH$

Now for the energy stored in the inductor at $At t = 1 s,$ $emf$

$U = \frac{1}{2} {LI}^{2} = \frac{1}{2} (0.625 \times 10^{- 3}) {(21)}^{2} = 0.137 J$

$P = Ei = (10 \times 10^{- 3}) (21) = 0.21 J / s$

The current in an inductor is given by $i = 5 + 16 t$ , where $i$ and $t$ are in ampere and second respectively. The induced $emf$ is $10 mV$ . Find out $(i)$ self-inductance and $(ii)$ the energy stored in the inductor at $t = 1$ second.

Important Questions on Electromagnetic Induction

Learn and Prepare for any exam you want !

The current in an inductor is given by i=5+16t, where i and t are in ampere and second respectively. The induced emf is 10 mV. Find out i self-inductance and ii the energy stored in the inductor at t=1 second.

Important Questions on Electromagnetic Induction

Learn and Prepare for any exam you want !

The current in an inductor is given by $i = 5 + 16 t$ , where $i$ and $t$ are in ampere and second respectively. The induced $emf$ is $10 mV$ . Find out $(i)$ self-inductance and $(ii)$ the energy stored in the inductor at $t = 1$ second.