1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
tresset_1 [31]
3 years ago
11

An inductor is connected to the terminals of a battery that has an emf of 12.0 V and negligible internal resistance. The current

is 4.86 mA at 0.725 ms after the connection is completed. After a long time, the current is 6.45 mA.
(a) What is the resistance R of the inductor?
(b) What is the inductance L of the inductor?
Physics
2 answers:
algol133 years ago
8 0

Answer:

R = 2481 Ω  

L= 1.67 H

Explanation:

(a) We have an inductor L which has an internal resistance of R. The inductor is connected to a battery with an emf of E = 12.0 V. So this circuit is equivalent to a simple RL circuit. It is given that the current is 4.86 mA at 0.725 ms after the connection is completed and is 6.45 mA after a long time. First we need to find the resistance of the inductor. The current flowing in an RL circuit is given by

i = E/R(1 -e^(-R/L)*t)                                                   (1)

at t --> ∞ the current is the maximum, that is,  

i_max = E/R

solve for R and substitute to get,  

R=  E/i_max

R = 2481 Ω  

(b) To find the inductance we will use i(t = 0.940 ms) = 4.86 mA, solve (1) for L as,  

Rt/L = - In (1  - i/i_max )

Or,  

L = - Rt/In (1  - i/i_max )

substitute with the givens to get,

L = -(2481 Si) (9.40 x 10-4 s)/ In (1  - 4.86/6.45 )  

L= 1.67 H

<u><em>note :</em></u>

<u><em>error maybe in calculation but method is correct</em></u>

yawa3891 [41]3 years ago
6 0
<h2>Answer:</h2>

(a) 1860 Ω

(b) 0.16H

<h2>Explanation:</h2>

This is an RL circuit as it contains an inductor with and inherent resistance.

The current, I, flowing through such circuit is given by;

I = \frac{E}{R}[1 - e^{-(R/L)t}]          --------------(i)

Where;

E = emf of the circuit = 12.0V

R = Resistance of the inductor

L = inductance of the inductor

t = time taken for the flow of current

(a) After a long time, i.e t → ∞, the current becomes saturated (i.e maximum) and the value is 6.45mA.

At this time, e^{-(R/L)t} (from equation (i)) becomes 0 and current I, becomes;

I = \frac{E}{R}   -------------------(ii)

Now substitute the value of E and I into equation (ii) as follows;

6.45 x 10⁻³= \frac{12.0}{R}

R = \frac{12.0}{6.45 * 10^{-3}}

R = 1860Ω

Therefore, the resistance of the inductor is 1860 Ω

(b) To get the inductance L of the inductor, we substitute I = 4.86mA at time t = 0.725ms into equation (i) as follows;

4.86 x 10⁻³ =  \frac{12.0}{1860}[1 - e^{-(1860/L)0.00486}]

4.86 x 10⁻³ x 1860 = 12.0[1 - e^{-(1860/L)0.00486}]

0.7533 = [1 - e^{-(1860/L)0.00486}]

1  - 0.7533 = e^{-(1860/L)0.00486}

0.2467 = e^{-(1860/L)0.00486}

Take the natural log of both sides

ln(0.2467) = -1860 x 0.00468 / L

-1.3996 = -8.7048 / L

L = -1.3996 / -8.7048

L = 0.16H

Therefore, the inductance of the inductor is 0.16H

You might be interested in
The box plots show the summer temperatures, in degrees Fahrenheit, in two cities. Summer Temperatures in City A Summer Temperatu
Inga [223]

Answer:b

Explanation:

7 0
3 years ago
Read 2 more answers
A mass attached to a spring vibrates back and forth. At maximum displacement, the spring force and the
Svetradugi [14.3K]

ANSWER

Velocity of the mass reaches zero

EXPLANATION

We want to identify what hapens to a mass attached toa a spring at maximum displacement.

When a mass attached to a spring is at its maximum position of displacement, the direction of the mass begins to change. This implies that the velocity of the mass will reach zero.

Hence, at maximum displacement, the velocity of the mass reaches zero.

8 0
11 months ago
Which of the following is numerically the same as the specific gravity? Mass Weight Density Volume
max2010maxim [7]
The answer is density

4 0
3 years ago
Read 2 more answers
Please help on this one?
Lynna [10]
Object distances are always negative according to the Cartesian sign convention
3 0
3 years ago
In the following reaction, which substance is the precipitate? (NH4)2SO4(aq) + Ba(NO3)2(aq) BaSO4(s) + 2NH4NO3(aq) (NH4)2SO4 Ba(
Mariana [72]
I think it's Barium sulfate, the soild and percipitate
4 0
3 years ago
Read 2 more answers
Other questions:
  • What did the scientist Robert Hooke claim ?
    6·2 answers
  • A boy pulls a wagon full of newspapers down the sidewalk at a constant acceleration. Suddenly, half the newspapers fall off the
    5·1 answer
  • The average induced emf will be given by the time rate of change and the product of the and the .
    15·1 answer
  • What is part of a line has one endpoint and continues in one direction?
    15·1 answer
  • A large number of very industrious people make a very long pole. It is 10.0 light years long! ( As they measure it. ) Soon a spa
    5·1 answer
  • A wave with a high amplitude______?
    13·1 answer
  • What component of the cell wall helps in growth and development, as well as keeping it strong to defend itself?
    6·1 answer
  • 1. The electromagnetic waves described in the reading are different in which two ways:
    10·1 answer
  • How much power is required to do 180 J of work in 2.4s?​
    13·2 answers
  • Name three types of variables in an experiment.
    5·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!