GATE Exam  >  GATE Questions  >  In a cylindrical conductor of radius 2mm, the... Start Learning for Free
In a cylindrical conductor of radius 2mm, the current density varies with the distance from the axis according to J = 103 (e)-400r A/m2. What is the value of the total current (I) (in mA) ?
Correct answer is '7.51'. Can you explain this answer?
Verified Answer
In a cylindrical conductor of radius 2mm, the current density varies w...
Total current (I)


I = 7.51 mA
View all questions of this test
Most Upvoted Answer
In a cylindrical conductor of radius 2mm, the current density varies w...
Given:
- Radius of the cylindrical conductor = 2 mm = 0.002 m
- Current density varies with the distance from the axis according to J = 103e^(-400r) A/m^2, where r is the distance from the axis in meters.

To find:
The value of the total current (I) in mA.

Explanation:
The total current (I) can be found by integrating the current density over the entire cross-sectional area of the cylindrical conductor.

Step 1: Finding the limits of integration:
Since the current density varies with the distance from the axis, the limits of integration will be from 0 to the radius of the conductor (0.002 m).

Step 2: Setting up the integral:
The current (dI) flowing through an infinitesimally small area (dA) located at a distance (r) from the axis can be given by dI = J * dA, where J is the current density.

Substituting the given expression for current density, we have dI = 103e^(-400r) * dA.

The total current (I) can be obtained by integrating the above expression over the entire cross-sectional area (A) of the conductor.

I = ∫[0 to 0.002] 103e^(-400r) * dA

Step 3: Evaluating the integral:
Since the conductor is cylindrical, the cross-sectional area (dA) can be given by dA = 2πr * dr.

Substituting the values in the integral equation, we have:
I = ∫[0 to 0.002] 103e^(-400r) * 2πr * dr

Integrating the above expression, we get:
I = [-51.5e^(-400r)πr^2] evaluated from 0 to 0.002

Evaluating the integral at the limits, we get:
I = [-51.5e^(-400 * 0.002) * π * (0.002)^2] - [-51.5e^(-400 * 0) * π * (0)^2]

Simplifying the above expression, we get:
I ≈ -51.5e^(-0.8) * π * (0.002)^2

Step 4: Converting the current to mA:
The above value of I is in Amperes. To convert it to milliamperes, we multiply it by 1000.

I ≈ -51.5e^(-0.8) * π * (0.002)^2 * 1000

Using a calculator, we find that I ≈ 7.51 mA.

Conclusion:
Therefore, the value of the total current (I) is approximately 7.51 mA.
Explore Courses for GATE exam

Similar GATE Doubts

In a cylindrical conductor of radius 2mm, the current density varies with the distance from the axis according to J = 103 (e)-400rA/m2. What is the value of the total current (I) (in mA) ?Correct answer is '7.51'. Can you explain this answer?
Question Description
In a cylindrical conductor of radius 2mm, the current density varies with the distance from the axis according to J = 103 (e)-400rA/m2. What is the value of the total current (I) (in mA) ?Correct answer is '7.51'. Can you explain this answer? for GATE 2024 is part of GATE preparation. The Question and answers have been prepared according to the GATE exam syllabus. Information about In a cylindrical conductor of radius 2mm, the current density varies with the distance from the axis according to J = 103 (e)-400rA/m2. What is the value of the total current (I) (in mA) ?Correct answer is '7.51'. Can you explain this answer? covers all topics & solutions for GATE 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for In a cylindrical conductor of radius 2mm, the current density varies with the distance from the axis according to J = 103 (e)-400rA/m2. What is the value of the total current (I) (in mA) ?Correct answer is '7.51'. Can you explain this answer?.
Solutions for In a cylindrical conductor of radius 2mm, the current density varies with the distance from the axis according to J = 103 (e)-400rA/m2. What is the value of the total current (I) (in mA) ?Correct answer is '7.51'. Can you explain this answer? in English & in Hindi are available as part of our courses for GATE. Download more important topics, notes, lectures and mock test series for GATE Exam by signing up for free.
Here you can find the meaning of In a cylindrical conductor of radius 2mm, the current density varies with the distance from the axis according to J = 103 (e)-400rA/m2. What is the value of the total current (I) (in mA) ?Correct answer is '7.51'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of In a cylindrical conductor of radius 2mm, the current density varies with the distance from the axis according to J = 103 (e)-400rA/m2. What is the value of the total current (I) (in mA) ?Correct answer is '7.51'. Can you explain this answer?, a detailed solution for In a cylindrical conductor of radius 2mm, the current density varies with the distance from the axis according to J = 103 (e)-400rA/m2. What is the value of the total current (I) (in mA) ?Correct answer is '7.51'. Can you explain this answer? has been provided alongside types of In a cylindrical conductor of radius 2mm, the current density varies with the distance from the axis according to J = 103 (e)-400rA/m2. What is the value of the total current (I) (in mA) ?Correct answer is '7.51'. Can you explain this answer? theory, EduRev gives you an ample number of questions to practice In a cylindrical conductor of radius 2mm, the current density varies with the distance from the axis according to J = 103 (e)-400rA/m2. What is the value of the total current (I) (in mA) ?Correct answer is '7.51'. Can you explain this answer? tests, examples and also practice GATE tests.
Explore Courses for GATE exam
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
10M+ students study on EduRev